xref: /frameworks/base/libs/androidfw/include/androidfw/ResourceTypes.h

/*
 * Copyright (C) 2005 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

//
// Definitions of resource data structures.
//
#ifndef _LIBS_UTILS_RESOURCE_TYPES_H
#define _LIBS_UTILS_RESOURCE_TYPES_H

#include <android-base/expected.h>
#include <android-base/unique_fd.h>
#include <android/configuration.h>
#include <androidfw/Asset.h>
#include <androidfw/Errors.h>
#include <androidfw/LocaleData.h>
#include <androidfw/StringPiece.h>
#include <utils/ByteOrder.h>
#include <utils/Errors.h>
#include <utils/KeyedVector.h>
#include <utils/String16.h>
#include <utils/Vector.h>
#include <utils/threads.h>

#include <stdint.h>
#include <sys/types.h>

#include <array>
#include <map>
#include <memory>
#include <optional>
#include <string_view>
#include <unordered_map>
#include <utility>

namespace android {

constexpr const bool kDeviceEndiannessSame = dtohs(0x1001) == 0x1001;

constexpr const uint32_t kIdmapMagic = 0x504D4449u;
constexpr const uint32_t kIdmapCurrentVersion = 0x0000000Bu;

// This must never change.
constexpr const uint32_t kFabricatedOverlayMagic = 0x4f525246; // FRRO (big endian)

// The version should only be changed when a backwards-incompatible change must be made to the
// fabricated overlay file format. Old fabricated overlays must be migrated to the new file format
// to prevent losing fabricated overlay data.
constexpr const uint32_t kFabricatedOverlayCurrentVersion = 3;

// Returns whether or not the path represents a fabricated overlay.
bool IsFabricatedOverlayName(std::string_view path);
bool IsFabricatedOverlay(std::string_view path);
bool IsFabricatedOverlay(android::base::borrowed_fd fd);

/**
 * In C++11, char16_t is defined as *at least* 16 bits. We do a lot of
 * casting on raw data and expect char16_t to be exactly 16 bits.
 */
#if __cplusplus >= 201103L
struct __assertChar16Size {
    static_assert(sizeof(char16_t) == sizeof(uint16_t), "char16_t is not 16 bits");
    static_assert(alignof(char16_t) == alignof(uint16_t), "char16_t is not 16-bit aligned");
};
#endif

/** ********************************************************************
 *  PNG Extensions
 *
 *  New private chunks that may be placed in PNG images.
 *
 *********************************************************************** */

/**
 * This chunk specifies how to split an image into segments for
 * scaling.
 *
 * There are J horizontal and K vertical segments.  These segments divide
 * the image into J*K regions as follows (where J=4 and K=3):
 *
 *      F0   S0    F1     S1
 *   +-----+----+------+-------+
 * S2|  0  |  1 |  2   |   3   |
 *   +-----+----+------+-------+
 *   |     |    |      |       |
 *   |     |    |      |       |
 * F2|  4  |  5 |  6   |   7   |
 *   |     |    |      |       |
 *   |     |    |      |       |
 *   +-----+----+------+-------+
 * S3|  8  |  9 |  10  |   11  |
 *   +-----+----+------+-------+
 *
 * Each horizontal and vertical segment is considered to by either
 * stretchable (marked by the Sx labels) or fixed (marked by the Fy
 * labels), in the horizontal or vertical axis, respectively. In the
 * above example, the first is horizontal segment (F0) is fixed, the
 * next is stretchable and then they continue to alternate. Note that
 * the segment list for each axis can begin or end with a stretchable
 * or fixed segment.
 *
 * The relative sizes of the stretchy segments indicates the relative
 * amount of stretchiness of the regions bordered by the segments.  For
 * example, regions 3, 7 and 11 above will take up more horizontal space
 * than regions 1, 5 and 9 since the horizontal segment associated with
 * the first set of regions is larger than the other set of regions.  The
 * ratios of the amount of horizontal (or vertical) space taken by any
 * two stretchable slices is exactly the ratio of their corresponding
 * segment lengths.
 *
 * xDivs and yDivs are arrays of horizontal and vertical pixel
 * indices.  The first pair of Divs (in either array) indicate the
 * starting and ending points of the first stretchable segment in that
 * axis. The next pair specifies the next stretchable segment, etc. So
 * in the above example xDiv[0] and xDiv[1] specify the horizontal
 * coordinates for the regions labeled 1, 5 and 9.  xDiv[2] and
 * xDiv[3] specify the coordinates for regions 3, 7 and 11. Note that
 * the leftmost slices always start at x=0 and the rightmost slices
 * always end at the end of the image. So, for example, the regions 0,
 * 4 and 8 (which are fixed along the X axis) start at x value 0 and
 * go to xDiv[0] and slices 2, 6 and 10 start at xDiv[1] and end at
 * xDiv[2].
 *
 * The colors array contains hints for each of the regions. They are
 * ordered according left-to-right and top-to-bottom as indicated above.
 * For each segment that is a solid color the array entry will contain
 * that color value; otherwise it will contain NO_COLOR. Segments that
 * are completely transparent will always have the value TRANSPARENT_COLOR.
 *
 * The PNG chunk type is "npTc".
 */
struct alignas(uintptr_t) Res_png_9patch
{
    Res_png_9patch() : wasDeserialized(false), xDivsOffset(0),
                       yDivsOffset(0), colorsOffset(0) { }

    int8_t wasDeserialized;
    uint8_t numXDivs;
    uint8_t numYDivs;
    uint8_t numColors;

    // The offset (from the start of this structure) to the xDivs & yDivs
    // array for this 9patch. To get a pointer to this array, call
    // getXDivs or getYDivs. Note that the serialized form for 9patches places
    // the xDivs, yDivs and colors arrays immediately after the location
    // of the Res_png_9patch struct.
    uint32_t xDivsOffset;
    uint32_t yDivsOffset;

    int32_t paddingLeft, paddingRight;
    int32_t paddingTop, paddingBottom;

    enum {
        // The 9 patch segment is not a solid color.
        NO_COLOR = 0x00000001,

        // The 9 patch segment is completely transparent.
        TRANSPARENT_COLOR = 0x00000000
    };

    // The offset (from the start of this structure) to the colors array
    // for this 9patch.
    uint32_t colorsOffset;

    // Convert data from device representation to PNG file representation.
    void deviceToFile();
    // Convert data from PNG file representation to device representation.
    void fileToDevice();

    // Serialize/Marshall the patch data into a newly malloc-ed block.
    static void* serialize(const Res_png_9patch& patchHeader, const int32_t* xDivs,
                           const int32_t* yDivs, const uint32_t* colors);
    // Serialize/Marshall the patch data into |outData|.
    static void serialize(const Res_png_9patch& patchHeader, const int32_t* xDivs,
                           const int32_t* yDivs, const uint32_t* colors, void* outData);
    // Deserialize/Unmarshall the patch data
    static Res_png_9patch* deserialize(void* data);
    // Compute the size of the serialized data structure
    size_t serializedSize() const;

    // These tell where the next section of a patch starts.
    // For example, the first patch includes the pixels from
    // 0 to xDivs[0]-1 and the second patch includes the pixels
    // from xDivs[0] to xDivs[1]-1.
    inline int32_t* getXDivs() const {
        return reinterpret_cast<int32_t*>(reinterpret_cast<uintptr_t>(this) + xDivsOffset);
    }
    inline int32_t* getYDivs() const {
        return reinterpret_cast<int32_t*>(reinterpret_cast<uintptr_t>(this) + yDivsOffset);
    }
    inline uint32_t* getColors() const {
        return reinterpret_cast<uint32_t*>(reinterpret_cast<uintptr_t>(this) + colorsOffset);
    }

} __attribute__((packed));

/** ********************************************************************
 *  Base Types
 *
 *  These are standard types that are shared between multiple specific
 *  resource types.
 *
 *********************************************************************** */

/**
 * Header that appears at the front of every data chunk in a resource.
 */
struct ResChunk_header
{
    // Type identifier for this chunk.  The meaning of this value depends
    // on the containing chunk.
    uint16_t type;

    // Size of the chunk header (in bytes).  Adding this value to
    // the address of the chunk allows you to find its associated data
    // (if any).
    uint16_t headerSize;

    // Total size of this chunk (in bytes).  This is the chunkSize plus
    // the size of any data associated with the chunk.  Adding this value
    // to the chunk allows you to completely skip its contents (including
    // any child chunks).  If this value is the same as chunkSize, there is
    // no data associated with the chunk.
    uint32_t size;
};

enum {
    RES_NULL_TYPE                     = 0x0000,
    RES_STRING_POOL_TYPE              = 0x0001,
    RES_TABLE_TYPE                    = 0x0002,
    RES_XML_TYPE                      = 0x0003,

    // Chunk types in RES_XML_TYPE
    RES_XML_FIRST_CHUNK_TYPE          = 0x0100,
    RES_XML_START_NAMESPACE_TYPE      = 0x0100,
    RES_XML_END_NAMESPACE_TYPE        = 0x0101,
    RES_XML_START_ELEMENT_TYPE        = 0x0102,
    RES_XML_END_ELEMENT_TYPE          = 0x0103,
    RES_XML_CDATA_TYPE                = 0x0104,
    RES_XML_LAST_CHUNK_TYPE           = 0x017f,
    // This contains a uint32_t array mapping strings in the string
    // pool back to resource identifiers.  It is optional.
    RES_XML_RESOURCE_MAP_TYPE         = 0x0180,

    // Chunk types in RES_TABLE_TYPE
    RES_TABLE_PACKAGE_TYPE            = 0x0200,
    RES_TABLE_TYPE_TYPE               = 0x0201,
    RES_TABLE_TYPE_SPEC_TYPE          = 0x0202,
    RES_TABLE_LIBRARY_TYPE            = 0x0203,
    RES_TABLE_OVERLAYABLE_TYPE        = 0x0204,
    RES_TABLE_OVERLAYABLE_POLICY_TYPE = 0x0205,
    RES_TABLE_STAGED_ALIAS_TYPE       = 0x0206,
};

/**
 * Macros for building/splitting resource identifiers.
 */
#define Res_VALIDID(resid) (resid != 0)
#define Res_CHECKID(resid) ((resid&0xFFFF0000) != 0)
#define Res_MAKEID(package, type, entry) \
    (((package+1)<<24) | (((type+1)&0xFF)<<16) | (entry&0xFFFF))
#define Res_GETPACKAGE(id) ((id>>24)-1)
#define Res_GETTYPE(id) (((id>>16)&0xFF)-1)
#define Res_GETENTRY(id) (id&0xFFFF)

#define Res_INTERNALID(resid) ((resid&0xFFFF0000) != 0 && (resid&0xFF0000) == 0)
#define Res_MAKEINTERNAL(entry) (0x01000000 | (entry&0xFFFF))
#define Res_MAKEARRAY(entry) (0x02000000 | (entry&0xFFFF))

static const size_t Res_MAXPACKAGE = 255;
static const size_t Res_MAXTYPE = 255;

/**
 * Representation of a value in a resource, supplying type
 * information.
 */
struct Res_value
{
    // Number of bytes in this structure.
    uint16_t size;

    // Always set to 0.
    uint8_t res0;

    // Type of the data value.
    enum : uint8_t {
        // The 'data' is either 0 or 1, specifying this resource is either
        // undefined or empty, respectively.
        TYPE_NULL = 0x00,
        // The 'data' holds a ResTable_ref, a reference to another resource
        // table entry.
        TYPE_REFERENCE = 0x01,
        // The 'data' holds an attribute resource identifier.
        TYPE_ATTRIBUTE = 0x02,
        // The 'data' holds an index into the containing resource table's
        // global value string pool.
        TYPE_STRING = 0x03,
        // The 'data' holds a single-precision floating point number.
        TYPE_FLOAT = 0x04,
        // The 'data' holds a complex number encoding a dimension value,
        // such as "100in".
        TYPE_DIMENSION = 0x05,
        // The 'data' holds a complex number encoding a fraction of a
        // container.
        TYPE_FRACTION = 0x06,
        // The 'data' holds a dynamic ResTable_ref, which needs to be
        // resolved before it can be used like a TYPE_REFERENCE.
        TYPE_DYNAMIC_REFERENCE = 0x07,
        // The 'data' holds an attribute resource identifier, which needs to be resolved
        // before it can be used like a TYPE_ATTRIBUTE.
        TYPE_DYNAMIC_ATTRIBUTE = 0x08,

        // Beginning of integer flavors...
        TYPE_FIRST_INT = 0x10,

        // The 'data' is a raw integer value of the form n..n.
        TYPE_INT_DEC = 0x10,
        // The 'data' is a raw integer value of the form 0xn..n.
        TYPE_INT_HEX = 0x11,
        // The 'data' is either 0 or 1, for input "false" or "true" respectively.
        TYPE_INT_BOOLEAN = 0x12,

        // Beginning of color integer flavors...
        TYPE_FIRST_COLOR_INT = 0x1c,

        // The 'data' is a raw integer value of the form #aarrggbb.
        TYPE_INT_COLOR_ARGB8 = 0x1c,
        // The 'data' is a raw integer value of the form #rrggbb.
        TYPE_INT_COLOR_RGB8 = 0x1d,
        // The 'data' is a raw integer value of the form #argb.
        TYPE_INT_COLOR_ARGB4 = 0x1e,
        // The 'data' is a raw integer value of the form #rgb.
        TYPE_INT_COLOR_RGB4 = 0x1f,

        // ...end of integer flavors.
        TYPE_LAST_COLOR_INT = 0x1f,

        // ...end of integer flavors.
        TYPE_LAST_INT = 0x1f
    };
    uint8_t dataType;

    // Structure of complex data values (TYPE_UNIT and TYPE_FRACTION)
    enum {
        // Where the unit type information is.  This gives us 16 possible
        // types, as defined below.
        COMPLEX_UNIT_SHIFT = 0,
        COMPLEX_UNIT_MASK = 0xf,

        // TYPE_DIMENSION: Value is raw pixels.
        COMPLEX_UNIT_PX = 0,
        // TYPE_DIMENSION: Value is Device Independent Pixels.
        COMPLEX_UNIT_DIP = 1,
        // TYPE_DIMENSION: Value is a Scaled device independent Pixels.
        COMPLEX_UNIT_SP = 2,
        // TYPE_DIMENSION: Value is in points.
        COMPLEX_UNIT_PT = 3,
        // TYPE_DIMENSION: Value is in inches.
        COMPLEX_UNIT_IN = 4,
        // TYPE_DIMENSION: Value is in millimeters.
        COMPLEX_UNIT_MM = 5,

        // TYPE_FRACTION: A basic fraction of the overall size.
        COMPLEX_UNIT_FRACTION = 0,
        // TYPE_FRACTION: A fraction of the parent size.
        COMPLEX_UNIT_FRACTION_PARENT = 1,

        // Where the radix information is, telling where the decimal place
        // appears in the mantissa.  This give us 4 possible fixed point
        // representations as defined below.
        COMPLEX_RADIX_SHIFT = 4,
        COMPLEX_RADIX_MASK = 0x3,

        // The mantissa is an integral number -- i.e., 0xnnnnnn.0
        COMPLEX_RADIX_23p0 = 0,
        // The mantissa magnitude is 16 bits -- i.e, 0xnnnn.nn
        COMPLEX_RADIX_16p7 = 1,
        // The mantissa magnitude is 8 bits -- i.e, 0xnn.nnnn
        COMPLEX_RADIX_8p15 = 2,
        // The mantissa magnitude is 0 bits -- i.e, 0x0.nnnnnn
        COMPLEX_RADIX_0p23 = 3,

        // Where the actual value is.  This gives us 23 bits of
        // precision.  The top bit is the sign.
        COMPLEX_MANTISSA_SHIFT = 8,
        COMPLEX_MANTISSA_MASK = 0xffffff
    };

    // Possible data values for TYPE_NULL.
    enum {
        // The value is not defined.
        DATA_NULL_UNDEFINED = 0,
        // The value is explicitly defined as empty.
        DATA_NULL_EMPTY = 1
    };

    // The data for this item, as interpreted according to dataType.
    typedef uint32_t data_type;
    data_type data;

    void copyFrom_dtoh(const Res_value& src) {
      if constexpr (kDeviceEndiannessSame) {
        *this = src;
      } else {
        copyFrom_dtoh_slow(src);
      }
    }

   private:
    void copyFrom_dtoh_slow(const Res_value& src);
};

/**
 *  This is a reference to a unique entry (a ResTable_entry structure)
 *  in a resource table.  The value is structured as: 0xpptteeee,
 *  where pp is the package index, tt is the type index in that
 *  package, and eeee is the entry index in that type.  The package
 *  and type values start at 1 for the first item, to help catch cases
 *  where they have not been supplied.
 */
struct ResTable_ref
{
    uint32_t ident;
};

/**
 * Reference to a string in a string pool.
 */
struct ResStringPool_ref
{
    // Index into the string pool table (uint32_t-offset from the indices
    // immediately after ResStringPool_header) at which to find the location
    // of the string data in the pool.
    uint32_t index;
};

/** ********************************************************************
 *  String Pool
 *
 *  A set of strings that can be references by others through a
 *  ResStringPool_ref.
 *
 *********************************************************************** */

/**
 * Definition for a pool of strings.  The data of this chunk is an
 * array of uint32_t providing indices into the pool, relative to
 * stringsStart.  At stringsStart are all of the UTF-16 strings
 * concatenated together; each starts with a uint16_t of the string's
 * length and each ends with a 0x0000 terminator.  If a string is >
 * 32767 characters, the high bit of the length is set meaning to take
 * those 15 bits as a high word and it will be followed by another
 * uint16_t containing the low word.
 *
 * If styleCount is not zero, then immediately following the array of
 * uint32_t indices into the string table is another array of indices
 * into a style table starting at stylesStart.  Each entry in the
 * style table is an array of ResStringPool_span structures.
 */
struct ResStringPool_header
{
    struct ResChunk_header header;

    // Number of strings in this pool (number of uint32_t indices that follow
    // in the data).
    uint32_t stringCount;

    // Number of style span arrays in the pool (number of uint32_t indices
    // follow the string indices).
    uint32_t styleCount;

    // Flags.
    enum {
        // If set, the string index is sorted by the string values (based
        // on strcmp16()).
        SORTED_FLAG = 1<<0,

        // String pool is encoded in UTF-8
        UTF8_FLAG = 1<<8
    };
    uint32_t flags;

    // Index from header of the string data.
    uint32_t stringsStart;

    // Index from header of the style data.
    uint32_t stylesStart;
};

/**
 * This structure defines a span of style information associated with
 * a string in the pool.
 */
struct ResStringPool_span
{
    enum {
        END = 0xFFFFFFFF
    };

    // This is the name of the span -- that is, the name of the XML
    // tag that defined it.  The special value END (0xFFFFFFFF) indicates
    // the end of an array of spans.
    ResStringPool_ref name;

    // The range of characters in the string that this span applies to.
    uint32_t firstChar, lastChar;
};

/**
 * Convenience class for accessing data in a ResStringPool resource.
 */
class ResStringPool
{
public:
 ResStringPool();
 explicit ResStringPool(bool optimize_name_lookups);
 ResStringPool(const void* data, size_t size, bool copyData = false,
               bool optimize_name_lookups = false);
 virtual ~ResStringPool();

 void setToEmpty();
 status_t setTo(incfs::map_ptr<void> data, size_t size, bool copyData = false);

 status_t getError() const;

 void uninit();

 // Return string entry as UTF16; if the pool is UTF8, the string will
 // be converted before returning.
 inline base::expected<StringPiece16, NullOrIOError> stringAt(const ResStringPool_ref& ref) const {
   return stringAt(ref.index);
 }
    virtual base::expected<StringPiece16, NullOrIOError> stringAt(size_t idx) const;

    // Note: returns null if the string pool is not UTF8.
    virtual base::expected<StringPiece, NullOrIOError> string8At(size_t idx) const;

    // Return string whether the pool is UTF8 or UTF16.  Does not allow you
    // to distinguish null.
    base::expected<String8, IOError> string8ObjectAt(size_t idx) const;

    base::expected<incfs::map_ptr<ResStringPool_span>, NullOrIOError> styleAt(
        const ResStringPool_ref& ref) const;
    base::expected<incfs::map_ptr<ResStringPool_span>, NullOrIOError> styleAt(size_t idx) const;

    base::expected<size_t, NullOrIOError> indexOfString(const char16_t* str, size_t strLen) const;

    virtual size_t size() const;
    size_t styleCount() const;
    size_t bytes() const;
    incfs::map_ptr<void> data() const;

    bool isSorted() const;
    bool isUTF8() const;

private:
    status_t                                      mError;
    void*                                         mOwnedData;
    incfs::verified_map_ptr<ResStringPool_header> mHeader;
    size_t                                        mSize;
    mutable Mutex                                 mCachesLock;
    incfs::map_ptr<uint32_t>                      mEntries;
    incfs::map_ptr<uint32_t>                      mEntryStyles;
    incfs::map_ptr<void>                          mStrings;
    char16_t mutable**                            mCache;
    uint32_t                                      mStringPoolSize;    // number of uint16_t
    incfs::map_ptr<uint32_t>                      mStyles;
    uint32_t                                      mStylePoolSize;    // number of uint32_t

    mutable std::optional<std::pair<std::unordered_map<std::string_view, int>,
                                    std::unordered_map<std::u16string_view, int>>>
        mIndexLookupCache;

    base::expected<StringPiece, NullOrIOError> stringDecodeAt(
        size_t idx, incfs::map_ptr<uint8_t> str, size_t encLen) const;
};

/**
 * Wrapper class that allows the caller to retrieve a string from
 * a string pool without knowing which string pool to look.
 */
class StringPoolRef {
public:
 StringPoolRef() = default;
 StringPoolRef(const ResStringPool* pool, uint32_t index);

 base::expected<StringPiece, NullOrIOError> string8() const;
 base::expected<StringPiece16, NullOrIOError> string16() const;

private:
 const ResStringPool* mPool = nullptr;
 uint32_t mIndex = 0u;
};

/** ********************************************************************
 *  XML Tree
 *
 *  Binary representation of an XML document.  This is designed to
 *  express everything in an XML document, in a form that is much
 *  easier to parse on the device.
 *
 *********************************************************************** */

/**
 * XML tree header.  This appears at the front of an XML tree,
 * describing its content.  It is followed by a flat array of
 * ResXMLTree_node structures; the hierarchy of the XML document
 * is described by the occurrance of RES_XML_START_ELEMENT_TYPE
 * and corresponding RES_XML_END_ELEMENT_TYPE nodes in the array.
 */
struct ResXMLTree_header
{
    struct ResChunk_header header;
};

/**
 * Basic XML tree node.  A single item in the XML document.  Extended info
 * about the node can be found after header.headerSize.
 */
struct ResXMLTree_node
{
    struct ResChunk_header header;

    // Line number in original source file at which this element appeared.
    uint32_t lineNumber;

    // Optional XML comment that was associated with this element; -1 if none.
    struct ResStringPool_ref comment;
};

/**
 * Extended XML tree node for CDATA tags -- includes the CDATA string.
 * Appears header.headerSize bytes after a ResXMLTree_node.
 */
struct ResXMLTree_cdataExt
{
    // The raw CDATA character data.
    struct ResStringPool_ref data;

    // The typed value of the character data if this is a CDATA node.
    struct Res_value typedData;
};

/**
 * Extended XML tree node for namespace start/end nodes.
 * Appears header.headerSize bytes after a ResXMLTree_node.
 */
struct ResXMLTree_namespaceExt
{
    // The prefix of the namespace.
    struct ResStringPool_ref prefix;

    // The URI of the namespace.
    struct ResStringPool_ref uri;
};

/**
 * Extended XML tree node for element start/end nodes.
 * Appears header.headerSize bytes after a ResXMLTree_node.
 */
struct ResXMLTree_endElementExt
{
    // String of the full namespace of this element.
    struct ResStringPool_ref ns;

    // String name of this node if it is an ELEMENT; the raw
    // character data if this is a CDATA node.
    struct ResStringPool_ref name;
};

/**
 * Extended XML tree node for start tags -- includes attribute
 * information.
 * Appears header.headerSize bytes after a ResXMLTree_node.
 */
struct ResXMLTree_attrExt
{
    // String of the full namespace of this element.
    struct ResStringPool_ref ns;

    // String name of this node if it is an ELEMENT; the raw
    // character data if this is a CDATA node.
    struct ResStringPool_ref name;

    // Byte offset from the start of this structure where the attributes start.
    uint16_t attributeStart;

    // Size of the ResXMLTree_attribute structures that follow.
    uint16_t attributeSize;

    // Number of attributes associated with an ELEMENT.  These are
    // available as an array of ResXMLTree_attribute structures
    // immediately following this node.
    uint16_t attributeCount;

    // Index (1-based) of the "id" attribute. 0 if none.
    uint16_t idIndex;

    // Index (1-based) of the "class" attribute. 0 if none.
    uint16_t classIndex;

    // Index (1-based) of the "style" attribute. 0 if none.
    uint16_t styleIndex;
};

struct ResXMLTree_attribute
{
    // Namespace of this attribute.
    struct ResStringPool_ref ns;

    // Name of this attribute.
    struct ResStringPool_ref name;

    // The original raw string value of this attribute.
    struct ResStringPool_ref rawValue;

    // Processesd typed value of this attribute.
    struct Res_value typedValue;
};

class ResXMLTree;

class ResXMLParser
{
public:
    explicit ResXMLParser(const ResXMLTree& tree);

    enum event_code_t {
        BAD_DOCUMENT = -1,
        START_DOCUMENT = 0,
        END_DOCUMENT = 1,

        FIRST_CHUNK_CODE = RES_XML_FIRST_CHUNK_TYPE,

        START_NAMESPACE = RES_XML_START_NAMESPACE_TYPE,
        END_NAMESPACE = RES_XML_END_NAMESPACE_TYPE,
        START_TAG = RES_XML_START_ELEMENT_TYPE,
        END_TAG = RES_XML_END_ELEMENT_TYPE,
        TEXT = RES_XML_CDATA_TYPE
    };

    struct ResXMLPosition
    {
        event_code_t                eventCode;
        const ResXMLTree_node*      curNode;
        const void*                 curExt;
    };

    void restart();

    const ResStringPool& getStrings() const;

    event_code_t getEventType() const;
    // Note, unlike XmlPullParser, the first call to next() will return
    // START_TAG of the first element.
    event_code_t next();

    // These are available for all nodes:
    int32_t getCommentID() const;
    const char16_t* getComment(size_t* outLen) const;
    uint32_t getLineNumber() const;

    // This is available for TEXT:
    int32_t getTextID() const;
    const char16_t* getText(size_t* outLen) const;
    ssize_t getTextValue(Res_value* outValue) const;

    // These are available for START_NAMESPACE and END_NAMESPACE:
    int32_t getNamespacePrefixID() const;
    const char16_t* getNamespacePrefix(size_t* outLen) const;
    int32_t getNamespaceUriID() const;
    const char16_t* getNamespaceUri(size_t* outLen) const;

    // These are available for START_TAG and END_TAG:
    int32_t getElementNamespaceID() const;
    const char16_t* getElementNamespace(size_t* outLen) const;
    int32_t getElementNameID() const;
    const char16_t* getElementName(size_t* outLen) const;

    // Remaining methods are for retrieving information about attributes
    // associated with a START_TAG:

    size_t getAttributeCount() const;

    // Returns -1 if no namespace, -2 if idx out of range.
    int32_t getAttributeNamespaceID(size_t idx) const;
    const char16_t* getAttributeNamespace(size_t idx, size_t* outLen) const;

    int32_t getAttributeNameID(size_t idx) const;
    const char16_t* getAttributeName(size_t idx, size_t* outLen) const;
    uint32_t getAttributeNameResID(size_t idx) const;

    // These will work only if the underlying string pool is UTF-8.
    const char* getAttributeNamespace8(size_t idx, size_t* outLen) const;
    const char* getAttributeName8(size_t idx, size_t* outLen) const;

    int32_t getAttributeValueStringID(size_t idx) const;
    const char16_t* getAttributeStringValue(size_t idx, size_t* outLen) const;

    int32_t getAttributeDataType(size_t idx) const;
    int32_t getAttributeData(size_t idx) const;
    ssize_t getAttributeValue(size_t idx, Res_value* outValue) const;

    ssize_t indexOfAttribute(const char* ns, const char* attr) const;
    ssize_t indexOfAttribute(const char16_t* ns, size_t nsLen,
                             const char16_t* attr, size_t attrLen) const;

    ssize_t indexOfID() const;
    ssize_t indexOfClass() const;
    ssize_t indexOfStyle() const;

    void getPosition(ResXMLPosition* pos) const;
    void setPosition(const ResXMLPosition& pos);

    void setSourceResourceId(const uint32_t resId);
    uint32_t getSourceResourceId() const;

private:
    friend class ResXMLTree;

    event_code_t nextNode();

    const ResXMLTree&           mTree;
    event_code_t                mEventCode;
    const ResXMLTree_node*      mCurNode;
    const void*                 mCurExt;
    uint32_t                    mSourceResourceId;
};

static inline bool operator==(const android::ResXMLParser::ResXMLPosition& lhs,
                              const android::ResXMLParser::ResXMLPosition& rhs) {
  return lhs.curNode == rhs.curNode;
}

class DynamicRefTable;

/**
 * Convenience class for accessing data in a ResXMLTree resource.
 */
class ResXMLTree : public ResXMLParser
{
public:
    /**
     * Creates a ResXMLTree with the specified DynamicRefTable for run-time package id translation.
     * The tree stores a clone of the specified DynamicRefTable, so any changes to the original
     * DynamicRefTable will not affect this tree after instantiation.
     **/
    explicit ResXMLTree(std::shared_ptr<const DynamicRefTable> dynamicRefTable);
    ResXMLTree();
    ~ResXMLTree();

    status_t setTo(const void* data, size_t size, bool copyData=false);

    status_t getError() const;

    void uninit();

private:
    friend class ResXMLParser;

    status_t validateNode(const ResXMLTree_node* node) const;

    std::shared_ptr<const DynamicRefTable> mDynamicRefTable;

    status_t                    mError;
    void*                       mOwnedData;
    const ResXMLTree_header*    mHeader;
    size_t                      mSize;
    const uint8_t*              mDataEnd;
    ResStringPool               mStrings;
    const uint32_t*             mResIds;
    size_t                      mNumResIds;
    const ResXMLTree_node*      mRootNode;
    const void*                 mRootExt;
    event_code_t                mRootCode;
};

/** ********************************************************************
 *  RESOURCE TABLE
 *
 *********************************************************************** */

/**
 * Header for a resource table.  Its data contains a series of
 * additional chunks:
 *   * A ResStringPool_header containing all table values.  This string pool
 *     contains all of the string values in the entire resource table (not
 *     the names of entries or type identifiers however).
 *   * One or more ResTable_package chunks.
 *
 * Specific entries within a resource table can be uniquely identified
 * with a single integer as defined by the ResTable_ref structure.
 */
struct ResTable_header
{
    struct ResChunk_header header;

    // The number of ResTable_package structures.
    uint32_t packageCount;
};

/**
 * A collection of resource data types within a package.  Followed by
 * one or more ResTable_type and ResTable_typeSpec structures containing the
 * entry values for each resource type.
 */
struct ResTable_package
{
    struct ResChunk_header header;

    // If this is a base package, its ID.  Package IDs start
    // at 1 (corresponding to the value of the package bits in a
    // resource identifier).  0 means this is not a base package.
    uint32_t id;

    // Actual name of this package, \0-terminated.
    uint16_t name[128];

    // Offset to a ResStringPool_header defining the resource
    // type symbol table.  If zero, this package is inheriting from
    // another base package (overriding specific values in it).
    uint32_t typeStrings;

    // Last index into typeStrings that is for public use by others.
    uint32_t lastPublicType;

    // Offset to a ResStringPool_header defining the resource
    // key symbol table.  If zero, this package is inheriting from
    // another base package (overriding specific values in it).
    uint32_t keyStrings;

    // Last index into keyStrings that is for public use by others.
    uint32_t lastPublicKey;

    uint32_t typeIdOffset;
};

// The most specific locale can consist of:
//
// - a 3 char language code
// - a 3 char region code prefixed by a 'r'
// - a 4 char script code prefixed by a 's'
// - a 8 char variant code prefixed by a 'v'
//
// each separated by a single char separator, which sums up to a total of 24
// chars, (25 include the string terminator). Numbering system specificator,
// if present, can add up to 14 bytes (-u-nu-xxxxxxxx), giving 39 bytes,
// or 40 bytes to make it 4 bytes aligned.
#define RESTABLE_MAX_LOCALE_LEN 40


/**
 * Describes a particular resource configuration.
 */
struct ResTable_config
{
    // Number of bytes in this structure.
    uint32_t size;

    union {
        struct {
            // Mobile country code (from SIM).  0 means "any".
            uint16_t mcc;
            // Mobile network code (from SIM).  0 means "any".
            uint16_t mnc;
        };
        uint32_t imsi;
    };

    union {
        struct {
            // This field can take three different forms:
            // - \0\0 means "any".
            //
            // - Two 7 bit ascii values interpreted as ISO-639-1 language
            //   codes ('fr', 'en' etc. etc.). The high bit for both bytes is
            //   zero.
            //
            // - A single 16 bit little endian packed value representing an
            //   ISO-639-2 3 letter language code. This will be of the form:
            //
            //   {1, t, t, t, t, t, s, s, s, s, s, f, f, f, f, f}
            //
            //   bit[0, 4] = first letter of the language code
            //   bit[5, 9] = second letter of the language code
            //   bit[10, 14] = third letter of the language code.
            //   bit[15] = 1 always
            //
            // For backwards compatibility, languages that have unambiguous
            // two letter codes are represented in that format.
            //
            // The layout is always bigendian irrespective of the runtime
            // architecture.
            char language[2];

            // This field can take three different forms:
            // - \0\0 means "any".
            //
            // - Two 7 bit ascii values interpreted as 2 letter region
            //   codes ('US', 'GB' etc.). The high bit for both bytes is zero.
            //
            // - An UN M.49 3 digit region code. For simplicity, these are packed
            //   in the same manner as the language codes, though we should need
            //   only 10 bits to represent them, instead of the 15.
            //
            // The layout is always bigendian irrespective of the runtime
            // architecture.
            char country[2];
        };
        uint32_t locale;
    };

    enum {
        ORIENTATION_ANY  = ACONFIGURATION_ORIENTATION_ANY,
        ORIENTATION_PORT = ACONFIGURATION_ORIENTATION_PORT,
        ORIENTATION_LAND = ACONFIGURATION_ORIENTATION_LAND,
        ORIENTATION_SQUARE = ACONFIGURATION_ORIENTATION_SQUARE,
    };

    enum {
        TOUCHSCREEN_ANY  = ACONFIGURATION_TOUCHSCREEN_ANY,
        TOUCHSCREEN_NOTOUCH  = ACONFIGURATION_TOUCHSCREEN_NOTOUCH,
        TOUCHSCREEN_STYLUS  = ACONFIGURATION_TOUCHSCREEN_STYLUS,
        TOUCHSCREEN_FINGER  = ACONFIGURATION_TOUCHSCREEN_FINGER,
    };

    enum {
        DENSITY_DEFAULT = ACONFIGURATION_DENSITY_DEFAULT,
        DENSITY_LOW = ACONFIGURATION_DENSITY_LOW,
        DENSITY_MEDIUM = ACONFIGURATION_DENSITY_MEDIUM,
        DENSITY_TV = ACONFIGURATION_DENSITY_TV,
        DENSITY_HIGH = ACONFIGURATION_DENSITY_HIGH,
        DENSITY_XHIGH = ACONFIGURATION_DENSITY_XHIGH,
        DENSITY_XXHIGH = ACONFIGURATION_DENSITY_XXHIGH,
        DENSITY_XXXHIGH = ACONFIGURATION_DENSITY_XXXHIGH,
        DENSITY_ANY = ACONFIGURATION_DENSITY_ANY,
        DENSITY_NONE = ACONFIGURATION_DENSITY_NONE
    };

    union {
        struct {
            uint8_t orientation;
            uint8_t touchscreen;
            uint16_t density;
        };
        uint32_t screenType;
    };

    enum {
        KEYBOARD_ANY  = ACONFIGURATION_KEYBOARD_ANY,
        KEYBOARD_NOKEYS  = ACONFIGURATION_KEYBOARD_NOKEYS,
        KEYBOARD_QWERTY  = ACONFIGURATION_KEYBOARD_QWERTY,
        KEYBOARD_12KEY  = ACONFIGURATION_KEYBOARD_12KEY,
    };

    enum {
        NAVIGATION_ANY  = ACONFIGURATION_NAVIGATION_ANY,
        NAVIGATION_NONAV  = ACONFIGURATION_NAVIGATION_NONAV,
        NAVIGATION_DPAD  = ACONFIGURATION_NAVIGATION_DPAD,
        NAVIGATION_TRACKBALL  = ACONFIGURATION_NAVIGATION_TRACKBALL,
        NAVIGATION_WHEEL  = ACONFIGURATION_NAVIGATION_WHEEL,
    };

    enum {
        MASK_KEYSHIDDEN = 0x0003,
        KEYSHIDDEN_ANY = ACONFIGURATION_KEYSHIDDEN_ANY,
        KEYSHIDDEN_NO = ACONFIGURATION_KEYSHIDDEN_NO,
        KEYSHIDDEN_YES = ACONFIGURATION_KEYSHIDDEN_YES,
        KEYSHIDDEN_SOFT = ACONFIGURATION_KEYSHIDDEN_SOFT,
    };

    enum {
        MASK_NAVHIDDEN = 0x000c,
        SHIFT_NAVHIDDEN = 2,
        NAVHIDDEN_ANY = ACONFIGURATION_NAVHIDDEN_ANY << SHIFT_NAVHIDDEN,
        NAVHIDDEN_NO = ACONFIGURATION_NAVHIDDEN_NO << SHIFT_NAVHIDDEN,
        NAVHIDDEN_YES = ACONFIGURATION_NAVHIDDEN_YES << SHIFT_NAVHIDDEN,
    };

    enum {
        GRAMMATICAL_GENDER_ANY = ACONFIGURATION_GRAMMATICAL_GENDER_ANY,
        GRAMMATICAL_GENDER_NEUTER = ACONFIGURATION_GRAMMATICAL_GENDER_NEUTER,
        GRAMMATICAL_GENDER_FEMININE = ACONFIGURATION_GRAMMATICAL_GENDER_FEMININE,
        GRAMMATICAL_GENDER_MASCULINE = ACONFIGURATION_GRAMMATICAL_GENDER_MASCULINE,
        GRAMMATICAL_INFLECTION_GENDER_MASK = 0b11,
    };

    struct {
        union {
            struct {
                uint8_t keyboard;
                uint8_t navigation;
                uint8_t inputFlags;
                uint8_t inputFieldPad0;
            };
            struct {
                uint32_t input : 24;
                uint32_t inputFullPad0 : 8;
            };
            struct {
                uint8_t grammaticalInflectionPad0[3];
                uint8_t grammaticalInflection;
            };
        };
    };

    enum {
        SCREENWIDTH_ANY = 0
    };

    enum {
        SCREENHEIGHT_ANY = 0
    };

    union {
        struct {
            uint16_t screenWidth;
            uint16_t screenHeight;
        };
        uint32_t screenSize;
    };

    enum {
        SDKVERSION_ANY = 0
    };

    enum {
        MINORVERSION_ANY = 0
    };

    union {
        struct {
            uint16_t sdkVersion;
            // For now minorVersion must always be 0!!!  Its meaning
            // is currently undefined.
            uint16_t minorVersion;
        };
        uint32_t version;
    };

    enum {
        // screenLayout bits for screen size class.
        MASK_SCREENSIZE = 0x0f,
        SCREENSIZE_ANY = ACONFIGURATION_SCREENSIZE_ANY,
        SCREENSIZE_SMALL = ACONFIGURATION_SCREENSIZE_SMALL,
        SCREENSIZE_NORMAL = ACONFIGURATION_SCREENSIZE_NORMAL,
        SCREENSIZE_LARGE = ACONFIGURATION_SCREENSIZE_LARGE,
        SCREENSIZE_XLARGE = ACONFIGURATION_SCREENSIZE_XLARGE,

        // screenLayout bits for wide/long screen variation.
        MASK_SCREENLONG = 0x30,
        SHIFT_SCREENLONG = 4,
        SCREENLONG_ANY = ACONFIGURATION_SCREENLONG_ANY << SHIFT_SCREENLONG,
        SCREENLONG_NO = ACONFIGURATION_SCREENLONG_NO << SHIFT_SCREENLONG,
        SCREENLONG_YES = ACONFIGURATION_SCREENLONG_YES << SHIFT_SCREENLONG,

        // screenLayout bits for layout direction.
        MASK_LAYOUTDIR = 0xC0,
        SHIFT_LAYOUTDIR = 6,
        LAYOUTDIR_ANY = ACONFIGURATION_LAYOUTDIR_ANY << SHIFT_LAYOUTDIR,
        LAYOUTDIR_LTR = ACONFIGURATION_LAYOUTDIR_LTR << SHIFT_LAYOUTDIR,
        LAYOUTDIR_RTL = ACONFIGURATION_LAYOUTDIR_RTL << SHIFT_LAYOUTDIR,
    };

    enum {
        // uiMode bits for the mode type.
        MASK_UI_MODE_TYPE = 0x0f,
        UI_MODE_TYPE_ANY = ACONFIGURATION_UI_MODE_TYPE_ANY,
        UI_MODE_TYPE_NORMAL = ACONFIGURATION_UI_MODE_TYPE_NORMAL,
        UI_MODE_TYPE_DESK = ACONFIGURATION_UI_MODE_TYPE_DESK,
        UI_MODE_TYPE_CAR = ACONFIGURATION_UI_MODE_TYPE_CAR,
        UI_MODE_TYPE_TELEVISION = ACONFIGURATION_UI_MODE_TYPE_TELEVISION,
        UI_MODE_TYPE_APPLIANCE = ACONFIGURATION_UI_MODE_TYPE_APPLIANCE,
        UI_MODE_TYPE_WATCH = ACONFIGURATION_UI_MODE_TYPE_WATCH,
        UI_MODE_TYPE_VR_HEADSET = ACONFIGURATION_UI_MODE_TYPE_VR_HEADSET,

        // uiMode bits for the night switch.
        MASK_UI_MODE_NIGHT = 0x30,
        SHIFT_UI_MODE_NIGHT = 4,
        UI_MODE_NIGHT_ANY = ACONFIGURATION_UI_MODE_NIGHT_ANY << SHIFT_UI_MODE_NIGHT,
        UI_MODE_NIGHT_NO = ACONFIGURATION_UI_MODE_NIGHT_NO << SHIFT_UI_MODE_NIGHT,
        UI_MODE_NIGHT_YES = ACONFIGURATION_UI_MODE_NIGHT_YES << SHIFT_UI_MODE_NIGHT,
    };

    union {
        struct {
            uint8_t screenLayout;
            uint8_t uiMode;
            uint16_t smallestScreenWidthDp;
        };
        uint32_t screenConfig;
    };

    union {
        struct {
            uint16_t screenWidthDp;
            uint16_t screenHeightDp;
        };
        uint32_t screenSizeDp;
    };

    // The ISO-15924 short name for the script corresponding to this
    // configuration. (eg. Hant, Latn, etc.). Interpreted in conjunction with
    // the locale field.
    char localeScript[4];

    // A single BCP-47 variant subtag. Will vary in length between 4 and 8
    // chars. Interpreted in conjunction with the locale field.
    char localeVariant[8];

    enum {
        // screenLayout2 bits for round/notround.
        MASK_SCREENROUND = 0x03,
        SCREENROUND_ANY = ACONFIGURATION_SCREENROUND_ANY,
        SCREENROUND_NO = ACONFIGURATION_SCREENROUND_NO,
        SCREENROUND_YES = ACONFIGURATION_SCREENROUND_YES,
    };

    enum {
        // colorMode bits for wide-color gamut/narrow-color gamut.
        MASK_WIDE_COLOR_GAMUT = 0x03,
        WIDE_COLOR_GAMUT_ANY = ACONFIGURATION_WIDE_COLOR_GAMUT_ANY,
        WIDE_COLOR_GAMUT_NO = ACONFIGURATION_WIDE_COLOR_GAMUT_NO,
        WIDE_COLOR_GAMUT_YES = ACONFIGURATION_WIDE_COLOR_GAMUT_YES,

        // colorMode bits for HDR/LDR.
        MASK_HDR = 0x0c,
        SHIFT_COLOR_MODE_HDR = 2,
        HDR_ANY = ACONFIGURATION_HDR_ANY << SHIFT_COLOR_MODE_HDR,
        HDR_NO = ACONFIGURATION_HDR_NO << SHIFT_COLOR_MODE_HDR,
        HDR_YES = ACONFIGURATION_HDR_YES << SHIFT_COLOR_MODE_HDR,
    };

    // An extension of screenConfig.
    union {
        struct {
            uint8_t screenLayout2;      // Contains round/notround qualifier.
            uint8_t colorMode;          // Wide-gamut, HDR, etc.
            uint16_t screenConfigPad2;  // Reserved padding.
        };
        uint32_t screenConfig2;
    };

    // If false and localeScript is set, it means that the script of the locale
    // was explicitly provided.
    //
    // If true, it means that localeScript was automatically computed.
    // localeScript may still not be set in this case, which means that we
    // tried but could not compute a script.
    bool localeScriptWasComputed;

    // The value of BCP 47 Unicode extension for key 'nu' (numbering system).
    // Varies in length from 3 to 8 chars. Zero-filled value.
    char localeNumberingSystem[8];

    // Mark all padding explicitly so it's clear how much we can expand it.
    char endPadding[3];

    void copyFromDeviceNoSwap(const ResTable_config& o) {
      const auto o_size = dtohl(o.size);
      if (o_size >= sizeof(ResTable_config)) [[likely]] {
        *this = o;
      } else {
        memcpy(this, &o, o_size);
        memset(((uint8_t*)this) + o_size, 0, sizeof(ResTable_config) - o_size);
      }
      this->size = sizeof(*this);
    }

    void copyFromDtoH(const ResTable_config& o) {
      if constexpr (kDeviceEndiannessSame) {
        copyFromDeviceNoSwap(o);
      } else {
        copyFromDtoH_slow(o);
      }
    }

    void swapHtoD() {
      if constexpr (kDeviceEndiannessSame) {
        ;  // noop
      } else {
        swapHtoD_slow();
      }
    }

    int compare(const ResTable_config& o) const;
    int compareLogical(const ResTable_config& o) const;

    inline bool operator<(const ResTable_config& o) const { return compare(o) < 0; }

    // Flags indicating a set of config values.  These flag constants must
    // match the corresponding ones in android.content.pm.ActivityInfo and
    // attrs_manifest.xml.
    enum {
        CONFIG_MCC = ACONFIGURATION_MCC,
        CONFIG_MNC = ACONFIGURATION_MNC,
        CONFIG_LOCALE = ACONFIGURATION_LOCALE,
        CONFIG_TOUCHSCREEN = ACONFIGURATION_TOUCHSCREEN,
        CONFIG_KEYBOARD = ACONFIGURATION_KEYBOARD,
        CONFIG_KEYBOARD_HIDDEN = ACONFIGURATION_KEYBOARD_HIDDEN,
        CONFIG_NAVIGATION = ACONFIGURATION_NAVIGATION,
        CONFIG_ORIENTATION = ACONFIGURATION_ORIENTATION,
        CONFIG_DENSITY = ACONFIGURATION_DENSITY,
        CONFIG_SCREEN_SIZE = ACONFIGURATION_SCREEN_SIZE,
        CONFIG_SMALLEST_SCREEN_SIZE = ACONFIGURATION_SMALLEST_SCREEN_SIZE,
        CONFIG_VERSION = ACONFIGURATION_VERSION,
        CONFIG_SCREEN_LAYOUT = ACONFIGURATION_SCREEN_LAYOUT,
        CONFIG_UI_MODE = ACONFIGURATION_UI_MODE,
        CONFIG_LAYOUTDIR = ACONFIGURATION_LAYOUTDIR,
        CONFIG_SCREEN_ROUND = ACONFIGURATION_SCREEN_ROUND,
        CONFIG_COLOR_MODE = ACONFIGURATION_COLOR_MODE,
        CONFIG_GRAMMATICAL_GENDER = ACONFIGURATION_GRAMMATICAL_GENDER,
    };

    // Compare two configuration, returning CONFIG_* flags set for each value
    // that is different.
    int diff(const ResTable_config& o) const;

    // Return true if 'this' is more specific than 'o'.
    bool isMoreSpecificThan(const ResTable_config& o) const;

    // Return true if 'this' is a better match than 'o' for the 'requested'
    // configuration.  This assumes that match() has already been used to
    // remove any configurations that don't match the requested configuration
    // at all; if they are not first filtered, non-matching results can be
    // considered better than matching ones.
    // The general rule per attribute: if the request cares about an attribute
    // (it normally does), if the two (this and o) are equal it's a tie.  If
    // they are not equal then one must be generic because only generic and
    // '==requested' will pass the match() call.  So if this is not generic,
    // it wins.  If this IS generic, o wins (return false).
    bool isBetterThan(const ResTable_config& o, const ResTable_config* requested) const;

    // Return true if 'this' can be considered a match for the parameters in
    // 'settings'.
    // Note this is asymetric.  A default piece of data will match every request
    // but a request for the default should not match odd specifics
    // (ie, request with no mcc should not match a particular mcc's data)
    // settings is the requested settings
    bool match(const ResTable_config& settings) const;

    // Get the string representation of the locale component of this
    // Config. The maximum size of this representation will be
    // |RESTABLE_MAX_LOCALE_LEN| (including a terminating '\0').
    //
    // Example: en-US, en-Latn-US, en-POSIX.
    //
    // If canonicalize is set, Tagalog (tl) locales get converted
    // to Filipino (fil).
    void getBcp47Locale(char* out, bool canonicalize=false) const;

    // Append to str the resource-qualifer string representation of the
    // locale component of this Config. If the locale is only country
    // and language, it will look like en-rUS. If it has scripts and
    // variants, it will be a modified bcp47 tag: b+en+Latn+US.
    void appendDirLocale(String8& str) const;

    // Sets the values of language, region, script, variant and numbering
    // system to the well formed BCP 47 locale contained in |in|.
    // The input locale is assumed to be valid and no validation is performed.
    void setBcp47Locale(const char* in);

    inline void clearLocale() {
        locale = 0;
        localeScriptWasComputed = false;
        memset(localeScript, 0, sizeof(localeScript));
        memset(localeVariant, 0, sizeof(localeVariant));
        memset(localeNumberingSystem, 0, sizeof(localeNumberingSystem));
    }

    inline void computeScript() {
        localeDataComputeScript(localeScript, language, country);
    }

    // Get the 2 or 3 letter language code of this configuration. Trailing
    // bytes are set to '\0'.
    size_t unpackLanguage(char language[4]) const;
    // Get the 2 or 3 letter language code of this configuration. Trailing
    // bytes are set to '\0'.
    size_t unpackRegion(char region[4]) const;

    // Sets the language code of this configuration to the first three
    // chars at |language|.
    //
    // If |language| is a 2 letter code, the trailing byte must be '\0' or
    // the BCP-47 separator '-'.
    void packLanguage(const char* language);
    // Sets the region code of this configuration to the first three bytes
    // at |region|. If |region| is a 2 letter code, the trailing byte must be '\0'
    // or the BCP-47 separator '-'.
    void packRegion(const char* region);

    // Returns a positive integer if this config is more specific than |o|
    // with respect to their locales, a negative integer if |o| is more specific
    // and 0 if they're equally specific.
    int isLocaleMoreSpecificThan(const ResTable_config &o) const;

    // Returns an integer representng the imporance score of the configuration locale.
    int getImportanceScoreOfLocale() const;

    // Return true if 'this' is a better locale match than 'o' for the
    // 'requested' configuration. Similar to isBetterThan(), this assumes that
    // match() has already been used to remove any configurations that don't
    // match the requested configuration at all.
    bool isLocaleBetterThan(const ResTable_config& o, const ResTable_config* requested) const;

    // The first part of isBetterThan() that only compares the fields that are higher priority than
    // the locale. Use it when you need to do custom locale matching to filter out the configs prior
    // to that.
    bool isBetterThanBeforeLocale(const ResTable_config& o, const ResTable_config& requested) const;

    String8 toString() const;

   private:
    void copyFromDtoH_slow(const ResTable_config& o);
    void swapHtoD_slow();
};

// Fix the struct size for backward compatibility
static_assert(sizeof(ResTable_config) == 64);

// Make sure there's no unaccounted padding in the structure.
static_assert(offsetof(ResTable_config, endPadding) +
                  sizeof(ResTable_config::endPadding) == sizeof(ResTable_config));

/**
 * A specification of the resources defined by a particular type.
 *
 * There should be one of these chunks for each resource type.
 *
 * This structure is followed by an array of integers providing the set of
 * configuration change flags (ResTable_config::CONFIG_*) that have multiple
 * resources for that configuration.  In addition, the high bit is set if that
 * resource has been made public.
 */
struct ResTable_typeSpec
{
    struct ResChunk_header header;

    // The type identifier this chunk is holding.  Type IDs start
    // at 1 (corresponding to the value of the type bits in a
    // resource identifier).  0 is invalid.
    uint8_t id;

    // Must be 0.
    uint8_t res0;
    // Used to be reserved, if >0 specifies the number of ResTable_type entries for this spec.
    uint16_t typesCount;

    // Number of uint32_t entry configuration masks that follow.
    uint32_t entryCount;

    enum : uint32_t {
        // Additional flag indicating an entry is public.
        SPEC_PUBLIC = 0x40000000u,

        // Additional flag indicating the resource id for this resource may change in a future
        // build. If this flag is set, the SPEC_PUBLIC flag is also set since the resource must be
        // public to be exposed as an API to other applications.
        SPEC_STAGED_API = 0x20000000u,
    };
};

/**
 * A collection of resource entries for a particular resource data
 * type.
 *
 * If the flag FLAG_SPARSE is not set in `flags`, then this struct is
 * followed by an array of uint32_t defining the resource
 * values, corresponding to the array of type strings in the
 * ResTable_package::typeStrings string block. Each of these hold an
 * index from entriesStart; a value of NO_ENTRY means that entry is
 * not defined.
 *
 * If the flag FLAG_SPARSE is set in `flags`, then this struct is followed
 * by an array of ResTable_sparseTypeEntry defining only the entries that
 * have values for this type. Each entry is sorted by their entry ID such
 * that a binary search can be performed over the entries. The ID and offset
 * are encoded in a uint32_t. See ResTabe_sparseTypeEntry.
 *
 * There may be multiple of these chunks for a particular resource type,
 * supply different configuration variations for the resource values of
 * that type.
 *
 * It would be nice to have an additional ordered index of entries, so
 * we can do a binary search if trying to find a resource by string name.
 */
struct ResTable_type
{
    struct ResChunk_header header;

    enum {
        NO_ENTRY = 0xFFFFFFFF
    };

    // The type identifier this chunk is holding.  Type IDs start
    // at 1 (corresponding to the value of the type bits in a
    // resource identifier).  0 is invalid.
    uint8_t id;

    enum {
        // If set, the entry is sparse, and encodes both the entry ID and offset into each entry,
        // and a binary search is used to find the key. Only available on platforms >= O.
        // Mark any types that use this with a v26 qualifier to prevent runtime issues on older
        // platforms.
        FLAG_SPARSE = 0x01,

        // If set, the offsets to the entries are encoded in 16-bit, real_offset = offset * 4u
        // An 16-bit offset of 0xffffu means a NO_ENTRY
        FLAG_OFFSET16 = 0x02,
    };
    uint8_t flags;

    // Must be 0.
    uint16_t reserved;

    // Number of uint32_t entry indices that follow.
    uint32_t entryCount;

    // Offset from header where ResTable_entry data starts.
    uint32_t entriesStart;

    // Configuration this collection of entries is designed for. This must always be last.
    ResTable_config config;
};

// Convert a 16-bit offset to 32-bit if FLAG_OFFSET16 is set
static inline uint32_t offset_from16(uint16_t off16) {
    return dtohs(off16) == 0xffffu ? ResTable_type::NO_ENTRY : dtohs(off16) * 4u;
}

// The minimum size required to read any version of ResTable_type.
constexpr size_t kResTableTypeMinSize =
    sizeof(ResTable_type) - sizeof(ResTable_config) + sizeof(ResTable_config::size);

// Assert that the ResTable_config is always the last field. This poses a problem for extending
// ResTable_type in the future, as ResTable_config is variable (over different releases).
static_assert(sizeof(ResTable_type) == offsetof(ResTable_type, config) + sizeof(ResTable_config),
              "ResTable_config must be last field in ResTable_type");

/**
 * An entry in a ResTable_type with the flag `FLAG_SPARSE` set.
 */
union ResTable_sparseTypeEntry {
    // Holds the raw uint32_t encoded value. Do not read this.
    uint32_t entry;
    struct {
        // The index of the entry.
        uint16_t idx;

        // The offset from ResTable_type::entriesStart, divided by 4.
        uint16_t offset;
    };
};

static_assert(sizeof(ResTable_sparseTypeEntry) == sizeof(uint32_t),
        "ResTable_sparseTypeEntry must be 4 bytes in size");

struct ResTable_map_entry;

/**
 * This is the beginning of information about an entry in the resource
 * table.  It holds the reference to the name of this entry, and is
 * immediately followed by one of:
 *   * A Res_value structure, if FLAG_COMPLEX is -not- set.
 *   * An array of ResTable_map structures, if FLAG_COMPLEX is set.
 *     These supply a set of name/value mappings of data.
 *   * If FLAG_COMPACT is set, this entry is a compact entry for
 *     simple values only
 */
union ResTable_entry
{
    enum {
        // If set, this is a complex entry, holding a set of name/value
        // mappings.  It is followed by an array of ResTable_map structures.
        FLAG_COMPLEX = 0x0001,
        // If set, this resource has been declared public, so libraries
        // are allowed to reference it.
        FLAG_PUBLIC = 0x0002,
        // If set, this is a weak resource and may be overriden by strong
        // resources of the same name/type. This is only useful during
        // linking with other resource tables.
        FLAG_WEAK = 0x0004,
        // If set, this is a compact entry with data type and value directly
        // encoded in the this entry, see ResTable_entry::compact
        FLAG_COMPACT = 0x0008,
        // If set, this entry relies on read write android feature flags
        FLAG_USES_FEATURE_FLAGS = 0x0010,
    };

    struct Full {
        // Number of bytes in this structure.
        uint16_t size;

        uint16_t flags;

        // Reference into ResTable_package::keyStrings identifying this entry.
        struct ResStringPool_ref key;
    } full;

    /* A compact entry is indicated by FLAG_COMPACT, with flags at the same
     * offset as a normal entry. This is only for simple data values where
     *
     * - size for entry or value can be inferred (both being 8 bytes).
     * - key index is encoded in 16-bit
     * - dataType is encoded as the higher 8-bit of flags
     * - data is encoded directly in this entry
     */
    struct Compact {
        uint16_t key;
        uint16_t flags;
        uint32_t data;
    } compact;

    uint16_t flags()  const { return dtohs(full.flags); };
    bool is_compact() const { return flags() & FLAG_COMPACT; }
    bool is_complex() const { return flags() & FLAG_COMPLEX; }
    bool uses_feature_flags() const { return flags() & FLAG_USES_FEATURE_FLAGS; }

    size_t size() const {
        return is_compact() ? sizeof(ResTable_entry) : dtohs(this->full.size);
    }

    uint32_t key() const {
        return is_compact() ? dtohs(this->compact.key) : dtohl(this->full.key.index);
    }

    /* Always verify the memory associated with this entry and its value
     * before calling value() or map_entry()
     */
    Res_value value() const {
        Res_value v;
        if (is_compact()) {
            v.size = sizeof(Res_value);
            v.res0 = 0;
            v.data = dtohl(this->compact.data);
            v.dataType = dtohs(compact.flags) >> 8;
        } else {
            auto vaddr = reinterpret_cast<const uint8_t*>(this) + dtohs(this->full.size);
            auto value = reinterpret_cast<const Res_value*>(vaddr);
            v.size = dtohs(value->size);
            v.res0 = value->res0;
            v.data = dtohl(value->data);
            v.dataType = value->dataType;
        }
        return v;
    }

    const ResTable_map_entry* map_entry() const {
        return is_complex() && !is_compact() ?
            reinterpret_cast<const ResTable_map_entry*>(this) : nullptr;
    }
};

/* Make sure size of ResTable_entry::Full and ResTable_entry::Compact
 * be the same as ResTable_entry. This is to allow iteration of entries
 * to work in either cases.
 *
 * The offset of flags must be at the same place for both structures,
 * to ensure the correct reading to decide whether this is a full entry
 * or a compact entry.
 */
static_assert(sizeof(ResTable_entry) == sizeof(ResTable_entry::Full));
static_assert(sizeof(ResTable_entry) == sizeof(ResTable_entry::Compact));
static_assert(offsetof(ResTable_entry, full.flags) == offsetof(ResTable_entry, compact.flags));

/**
 * Extended form of a ResTable_entry for map entries, defining a parent map
 * resource from which to inherit values.
 */
struct ResTable_map_entry : public ResTable_entry::Full
{
    // Resource identifier of the parent mapping, or 0 if there is none.
    // This is always treated as a TYPE_DYNAMIC_REFERENCE.
    ResTable_ref parent;
    // Number of name/value pairs that follow for FLAG_COMPLEX.
    uint32_t count;
};

/**
 * A single name/value mapping that is part of a complex resource
 * entry.
 */
struct ResTable_map
{
    // The resource identifier defining this mapping's name.  For attribute
    // resources, 'name' can be one of the following special resource types
    // to supply meta-data about the attribute; for all other resource types
    // it must be an attribute resource.
    ResTable_ref name;

    // Special values for 'name' when defining attribute resources.
    enum {
        // This entry holds the attribute's type code.
        ATTR_TYPE = Res_MAKEINTERNAL(0),

        // For integral attributes, this is the minimum value it can hold.
        ATTR_MIN = Res_MAKEINTERNAL(1),

        // For integral attributes, this is the maximum value it can hold.
        ATTR_MAX = Res_MAKEINTERNAL(2),

        // Localization of this resource is can be encouraged or required with
        // an aapt flag if this is set
        ATTR_L10N = Res_MAKEINTERNAL(3),

        // for plural support, see android.content.res.PluralRules#attrForQuantity(int)
        ATTR_OTHER = Res_MAKEINTERNAL(4),
        ATTR_ZERO = Res_MAKEINTERNAL(5),
        ATTR_ONE = Res_MAKEINTERNAL(6),
        ATTR_TWO = Res_MAKEINTERNAL(7),
        ATTR_FEW = Res_MAKEINTERNAL(8),
        ATTR_MANY = Res_MAKEINTERNAL(9)

    };

    // Bit mask of allowed types, for use with ATTR_TYPE.
    enum {
        // No type has been defined for this attribute, use generic
        // type handling.  The low 16 bits are for types that can be
        // handled generically; the upper 16 require additional information
        // in the bag so can not be handled generically for TYPE_ANY.
        TYPE_ANY = 0x0000FFFF,

        // Attribute holds a references to another resource.
        TYPE_REFERENCE = 1<<0,

        // Attribute holds a generic string.
        TYPE_STRING = 1<<1,

        // Attribute holds an integer value.  ATTR_MIN and ATTR_MIN can
        // optionally specify a constrained range of possible integer values.
        TYPE_INTEGER = 1<<2,

        // Attribute holds a boolean integer.
        TYPE_BOOLEAN = 1<<3,

        // Attribute holds a color value.
        TYPE_COLOR = 1<<4,

        // Attribute holds a floating point value.
        TYPE_FLOAT = 1<<5,

        // Attribute holds a dimension value, such as "20px".
        TYPE_DIMENSION = 1<<6,

        // Attribute holds a fraction value, such as "20%".
        TYPE_FRACTION = 1<<7,

        // Attribute holds an enumeration.  The enumeration values are
        // supplied as additional entries in the map.
        TYPE_ENUM = 1<<16,

        // Attribute holds a bitmaks of flags.  The flag bit values are
        // supplied as additional entries in the map.
        TYPE_FLAGS = 1<<17
    };

    // Enum of localization modes, for use with ATTR_L10N.
    enum {
        L10N_NOT_REQUIRED = 0,
        L10N_SUGGESTED    = 1
    };

    // This mapping's value.
    Res_value value;
};

/**
 * A package-id to package name mapping for any shared libraries used
 * in this resource table. The package-id's encoded in this resource
 * table may be different than the id's assigned at runtime. We must
 * be able to translate the package-id's based on the package name.
 */
struct ResTable_lib_header
{
    struct ResChunk_header header;

    // The number of shared libraries linked in this resource table.
    uint32_t count;
};

/**
 * A shared library package-id to package name entry.
 */
struct ResTable_lib_entry
{
    // The package-id this shared library was assigned at build time.
    // We use a uint32 to keep the structure aligned on a uint32 boundary.
    uint32_t packageId;

    // The package name of the shared library. \0 terminated.
    uint16_t packageName[128];
};

/**
 * A map that allows rewriting staged (non-finalized) resource ids to their finalized counterparts.
 */
struct ResTable_staged_alias_header
{
    struct ResChunk_header header;

    // The number of ResTable_staged_alias_entry that follow this header.
    uint32_t count;
};

/**
 * Maps the staged (non-finalized) resource id to its finalized resource id.
 */
struct ResTable_staged_alias_entry
{
  // The compile-time staged resource id to rewrite.
  uint32_t stagedResId;

  // The compile-time finalized resource id to which the staged resource id should be rewritten.
  uint32_t finalizedResId;
};

/**
 * Specifies the set of resources that are explicitly allowed to be overlaid by RROs.
 */
struct ResTable_overlayable_header
{
  struct ResChunk_header header;

  // The name of the overlayable set of resources that overlays target.
  uint16_t name[256];

 // The component responsible for enabling and disabling overlays targeting this chunk.
  uint16_t actor[256];
};

/**
 * Holds a list of resource ids that are protected from being overlaid by a set of policies. If
 * the overlay fulfils at least one of the policies, then the overlay can overlay the list of
 * resources.
 */
struct ResTable_overlayable_policy_header
{
  /**
   * Flags for a bitmask for all possible overlayable policy options.
   *
   * Any changes to this set should also update aidl/android/os/OverlayablePolicy.aidl
   */
  enum PolicyFlags : uint32_t {
    // Base
    NONE = 0x00000000,

    // Any overlay can overlay these resources.
    PUBLIC = 0x00000001,

    // The overlay must reside of the system partition or must have existed on the system partition
    // before an upgrade to overlay these resources.
    SYSTEM_PARTITION = 0x00000002,

    // The overlay must reside of the vendor partition or must have existed on the vendor partition
    // before an upgrade to overlay these resources.
    VENDOR_PARTITION = 0x00000004,

    // The overlay must reside of the product partition or must have existed on the product
    // partition before an upgrade to overlay these resources.
    PRODUCT_PARTITION = 0x00000008,

    // The overlay must be signed with the same signature as the package containing the target
    // resource
    SIGNATURE = 0x00000010,

    // The overlay must reside of the odm partition or must have existed on the odm
    // partition before an upgrade to overlay these resources.
    ODM_PARTITION = 0x00000020,

    // The overlay must reside of the oem partition or must have existed on the oem
    // partition before an upgrade to overlay these resources.
    OEM_PARTITION = 0x00000040,

    // The overlay must be signed with the same signature as the actor declared for the target
    // resource
    ACTOR_SIGNATURE = 0x00000080,

    // The overlay must be signed with the same signature as the reference package declared
    // in the SystemConfig
    CONFIG_SIGNATURE = 0x00000100,
  };

  using PolicyBitmask = uint32_t;

  struct ResChunk_header header;

  PolicyFlags policy_flags;

  // The number of ResTable_ref that follow this header.
  uint32_t entry_count;
};

inline ResTable_overlayable_policy_header::PolicyFlags& operator |=(
    ResTable_overlayable_policy_header::PolicyFlags& first,
    ResTable_overlayable_policy_header::PolicyFlags second) {
  first = static_cast<ResTable_overlayable_policy_header::PolicyFlags>(first | second);
  return first;
}

using ResourceId = uint32_t;  // 0xpptteeee

using DataType = uint8_t;    // Res_value::dataType
using DataValue = uint32_t;  // Res_value::data

struct OverlayManifestInfo {
  std::string package_name;     // NOLINT(misc-non-private-member-variables-in-classes)
  std::string name;             // NOLINT(misc-non-private-member-variables-in-classes)
  std::string target_package;   // NOLINT(misc-non-private-member-variables-in-classes)
  std::string target_name;      // NOLINT(misc-non-private-member-variables-in-classes)
  ResourceId resource_mapping;  // NOLINT(misc-non-private-member-variables-in-classes)
};

struct FabricatedOverlayEntryParameters {
  std::string resource_name;
  DataType data_type;
  DataValue data_value;
  std::string data_string_value;
  std::optional<android::base::borrowed_fd> data_binary_value;
  off64_t binary_data_offset;
  size_t binary_data_size;
  std::string configuration;
  bool nine_patch;
};

class AssetManager2;

/**
 * Holds the shared library ID table. Shared libraries are assigned package IDs at
 * build time, but they may be loaded in a different order, so we need to maintain
 * a mapping of build-time package ID to run-time assigned package ID.
 *
 * Dynamic references are not currently supported in overlays. Only the base package
 * may have dynamic references.
 */
class DynamicRefTable
{
    friend class AssetManager2;
public:
    DynamicRefTable();
    DynamicRefTable(uint8_t packageId, bool appAsLib);
    virtual ~DynamicRefTable() = default;

    // Loads an unmapped reference table from the package.
    status_t load(const ResTable_lib_header* const header);

    // Adds mappings from the other DynamicRefTable
    status_t addMappings(const DynamicRefTable& other);

    // Creates a mapping from build-time package ID to run-time package ID for
    // the given package.
    status_t addMapping(const String16& packageName, uint8_t packageId);

    void addMapping(uint8_t buildPackageId, uint8_t runtimePackageId);

    using AliasMap = std::vector<std::pair<uint32_t, uint32_t>>;
    void setAliases(AliasMap aliases) {
        mAliasId = std::move(aliases);
    }

    // Returns whether or not the value must be looked up.
    bool requiresLookup(const Res_value* value) const;

    // Performs the actual conversion of build-time resource ID to run-time
    // resource ID.
    virtual status_t lookupResourceId(uint32_t* resId) const;
    status_t lookupResourceValue(Res_value* value) const;

    inline const KeyedVector<String16, uint8_t>& entries() const {
        return mEntries;
    }

   private:
    uint8_t mLookupTable[256];
    uint8_t mAssignedPackageId;
    bool mAppAsLib;
    KeyedVector<String16, uint8_t> mEntries;
    AliasMap mAliasId;
};

bool U16StringToInt(const char16_t* s, size_t len, Res_value* outValue);

template<typename TChar, typename E>
static const TChar* UnpackOptionalString(base::expected<BasicStringPiece<TChar>, E>&& result,
                                         size_t* outLen) {
  if (result.has_value()) {
    *outLen = result->size();
    return result->data();
  }
  return NULL;
}

/**
 * Convenience class for accessing data in a ResTable resource.
 */
class ResTable
{
public:
    ResTable();
    ResTable(const void* data, size_t size, const int32_t cookie,
             bool copyData=false);
    ~ResTable();

    status_t add(const void* data, size_t size, const int32_t cookie=-1, bool copyData=false);
    status_t add(const void* data, size_t size, const void* idmapData, size_t idmapDataSize,
            const int32_t cookie=-1, bool copyData=false, bool appAsLib=false);

    status_t add(Asset* asset, const int32_t cookie=-1, bool copyData=false);
    status_t add(Asset* asset, Asset* idmapAsset, const int32_t cookie=-1, bool copyData=false,
            bool appAsLib=false, bool isSystemAsset=false);

    status_t add(ResTable* src, bool isSystemAsset=false);
    status_t addEmpty(const int32_t cookie);

    status_t getError() const;

    void uninit();

    struct resource_name
    {
        const char16_t* package = NULL;
        size_t packageLen;
        const char16_t* type = NULL;
        const char* type8 = NULL;
        size_t typeLen;
        const char16_t* name = NULL;
        const char* name8 = NULL;
        size_t nameLen;
    };

    bool getResourceName(uint32_t resID, bool allowUtf8, resource_name* outName) const;

    bool getResourceFlags(uint32_t resID, uint32_t* outFlags) const;

    bool getResourceEntryFlags(uint32_t resID, uint32_t* outFlags) const;

    /**
     * Returns whether or not the package for the given resource has been dynamically assigned.
     * If the resource can't be found, returns 'false'.
     */
    bool isResourceDynamic(uint32_t resID) const;

    /**
     * Returns whether or not the given package has been dynamically assigned.
     * If the package can't be found, returns 'false'.
     */
    bool isPackageDynamic(uint8_t packageID) const;

    /**
     * Retrieve the value of a resource.  If the resource is found, returns a
     * value >= 0 indicating the table it is in (for use with
     * getTableStringBlock() and getTableCookie()) and fills in 'outValue'.  If
     * not found, returns a negative error code.
     *
     * Note that this function does not do reference traversal.  If you want
     * to follow references to other resources to get the "real" value to
     * use, you need to call resolveReference() after this function.
     *
     * @param resID The desired resoruce identifier.
     * @param outValue Filled in with the resource data that was found.
     *
     * @return ssize_t Either a >= 0 table index or a negative error code.
     */
    ssize_t getResource(uint32_t resID, Res_value* outValue, bool mayBeBag = false,
                    uint16_t density = 0,
                    uint32_t* outSpecFlags = NULL,
                    ResTable_config* outConfig = NULL) const;

    inline ssize_t getResource(const ResTable_ref& res, Res_value* outValue,
            uint32_t* outSpecFlags=NULL) const {
        return getResource(res.ident, outValue, false, 0, outSpecFlags, NULL);
    }

    ssize_t resolveReference(Res_value* inOutValue,
                             ssize_t blockIndex,
                             uint32_t* outLastRef = NULL,
                             uint32_t* inoutTypeSpecFlags = NULL,
                             ResTable_config* outConfig = NULL) const;

    enum {
        TMP_BUFFER_SIZE = 16
    };
    const char16_t* valueToString(const Res_value* value, size_t stringBlock,
                                  char16_t tmpBuffer[TMP_BUFFER_SIZE],
                                  size_t* outLen) const;

    struct bag_entry {
        ssize_t stringBlock;
        ResTable_map map;
    };

    /**
     * Retrieve the bag of a resource.  If the resoruce is found, returns the
     * number of bags it contains and 'outBag' points to an array of their
     * values.  If not found, a negative error code is returned.
     *
     * Note that this function -does- do reference traversal of the bag data.
     *
     * @param resID The desired resource identifier.
     * @param outBag Filled inm with a pointer to the bag mappings.
     *
     * @return ssize_t Either a >= 0 bag count of negative error code.
     */
    ssize_t lockBag(uint32_t resID, const bag_entry** outBag) const;

    void unlockBag(const bag_entry* bag) const;

    void lock() const;

    ssize_t getBagLocked(uint32_t resID, const bag_entry** outBag,
            uint32_t* outTypeSpecFlags=NULL) const;

    void unlock() const;

    class Theme {
    public:
        explicit Theme(const ResTable& table);
        ~Theme();

        inline const ResTable& getResTable() const { return mTable; }

        status_t applyStyle(uint32_t resID, bool force=false);
        status_t setTo(const Theme& other);
        status_t clear();

        /**
         * Retrieve a value in the theme.  If the theme defines this
         * value, returns a value >= 0 indicating the table it is in
         * (for use with getTableStringBlock() and getTableCookie) and
         * fills in 'outValue'.  If not found, returns a negative error
         * code.
         *
         * Note that this function does not do reference traversal.  If you want
         * to follow references to other resources to get the "real" value to
         * use, you need to call resolveReference() after this function.
         *
         * @param resID A resource identifier naming the desired theme
         *              attribute.
         * @param outValue Filled in with the theme value that was
         *                 found.
         *
         * @return ssize_t Either a >= 0 table index or a negative error code.
         */
        ssize_t getAttribute(uint32_t resID, Res_value* outValue,
                uint32_t* outTypeSpecFlags = NULL) const;

        /**
         * This is like ResTable::resolveReference(), but also takes
         * care of resolving attribute references to the theme.
         */
        ssize_t resolveAttributeReference(Res_value* inOutValue,
                ssize_t blockIndex, uint32_t* outLastRef = NULL,
                uint32_t* inoutTypeSpecFlags = NULL,
                ResTable_config* inoutConfig = NULL) const;

        /**
         * Returns a bit mask of configuration changes that will impact this
         * theme (and thus require completely reloading it).
         */
        uint32_t getChangingConfigurations() const;

        void dumpToLog() const;

    private:
        Theme(const Theme&);
        Theme& operator=(const Theme&);

        struct theme_entry {
            ssize_t stringBlock;
            uint32_t typeSpecFlags;
            Res_value value;
        };

        struct type_info {
            size_t numEntries;
            theme_entry* entries;
        };

        struct package_info {
            type_info types[Res_MAXTYPE + 1];
        };

        void free_package(package_info* pi);
        package_info* copy_package(package_info* pi);

        const ResTable& mTable;
        package_info*   mPackages[Res_MAXPACKAGE];
        uint32_t        mTypeSpecFlags;
    };

    void setParameters(const ResTable_config* params);
    void getParameters(ResTable_config* params) const;

    // Retrieve an identifier (which can be passed to getResource)
    // for a given resource name.  The 'name' can be fully qualified
    // (<package>:<type>.<basename>) or the package or type components
    // can be dropped if default values are supplied here.
    //
    // Returns 0 if no such resource was found, else a valid resource ID.
    uint32_t identifierForName(const char16_t* name, size_t nameLen,
                               const char16_t* type = 0, size_t typeLen = 0,
                               const char16_t* defPackage = 0,
                               size_t defPackageLen = 0,
                               uint32_t* outTypeSpecFlags = NULL) const;

    static bool expandResourceRef(const char16_t* refStr, size_t refLen,
                                  String16* outPackage,
                                  String16* outType,
                                  String16* outName,
                                  const String16* defType = NULL,
                                  const String16* defPackage = NULL,
                                  const char** outErrorMsg = NULL,
                                  bool* outPublicOnly = NULL);

    static bool stringToInt(const char16_t* s, size_t len, Res_value* outValue);
    static bool stringToFloat(const char16_t* s, size_t len, Res_value* outValue);
    static bool stringToDouble(const char16_t* s, size_t len, double& outValue);

    // Used with stringToValue.
    class Accessor
    {
    public:
        inline virtual ~Accessor() { }

        virtual const String16& getAssetsPackage() const = 0;

        virtual uint32_t getCustomResource(const String16& package,
                                           const String16& type,
                                           const String16& name) const = 0;
        virtual uint32_t getCustomResourceWithCreation(const String16& package,
                                                       const String16& type,
                                                       const String16& name,
                                                       const bool createIfNeeded = false) = 0;
        virtual uint32_t getRemappedPackage(uint32_t origPackage) const = 0;
        virtual bool getAttributeType(uint32_t attrID, uint32_t* outType) = 0;
        virtual bool getAttributeMin(uint32_t attrID, uint32_t* outMin) = 0;
        virtual bool getAttributeMax(uint32_t attrID, uint32_t* outMax) = 0;
        virtual bool getAttributeEnum(uint32_t attrID,
                                      const char16_t* name, size_t nameLen,
                                      Res_value* outValue) = 0;
        virtual bool getAttributeFlags(uint32_t attrID,
                                       const char16_t* name, size_t nameLen,
                                       Res_value* outValue) = 0;
        virtual uint32_t getAttributeL10N(uint32_t attrID) = 0;
        virtual bool getLocalizationSetting() = 0;
        virtual void reportError(void* accessorCookie, const char* fmt, ...) = 0;
    };

    // Convert a string to a resource value.  Handles standard "@res",
    // "#color", "123", and "0x1bd" types; performs escaping of strings.
    // The resulting value is placed in 'outValue'; if it is a string type,
    // 'outString' receives the string.  If 'attrID' is supplied, the value is
    // type checked against this attribute and it is used to perform enum
    // evaluation.  If 'acccessor' is supplied, it will be used to attempt to
    // resolve resources that do not exist in this ResTable.  If 'attrType' is
    // supplied, the value will be type checked for this format if 'attrID'
    // is not supplied or found.
    bool stringToValue(Res_value* outValue, String16* outString,
                       const char16_t* s, size_t len,
                       bool preserveSpaces, bool coerceType,
                       uint32_t attrID = 0,
                       const String16* defType = NULL,
                       const String16* defPackage = NULL,
                       Accessor* accessor = NULL,
                       void* accessorCookie = NULL,
                       uint32_t attrType = ResTable_map::TYPE_ANY,
                       bool enforcePrivate = true) const;

    // Perform processing of escapes and quotes in a string.
    static bool collectString(String16* outString,
                              const char16_t* s, size_t len,
                              bool preserveSpaces,
                              const char** outErrorMsg = NULL,
                              bool append = false);

    size_t getBasePackageCount() const;
    const String16 getBasePackageName(size_t idx) const;
    uint32_t getBasePackageId(size_t idx) const;
    uint32_t getLastTypeIdForPackage(size_t idx) const;

    // Return the number of resource tables that the object contains.
    size_t getTableCount() const;
    // Return the values string pool for the resource table at the given
    // index.  This string pool contains all of the strings for values
    // contained in the resource table -- that is the item values themselves,
    // but not the names their entries or types.
    const ResStringPool* getTableStringBlock(size_t index) const;
    // Return unique cookie identifier for the given resource table.
    int32_t getTableCookie(size_t index) const;

    const DynamicRefTable* getDynamicRefTableForCookie(int32_t cookie) const;

    // Return the configurations (ResTable_config) that we know about
    void getConfigurations(Vector<ResTable_config>* configs, bool ignoreMipmap=false,
            bool ignoreAndroidPackage=false, bool includeSystemConfigs=true) const;

    void getLocales(Vector<String8>* locales, bool includeSystemLocales=true,
            bool mergeEquivalentLangs=false) const;

    // Generate an idmap.
    //
    // Return value: on success: NO_ERROR; caller is responsible for free-ing
    // outData (using free(3)). On failure, any status_t value other than
    // NO_ERROR; the caller should not free outData.
    status_t createIdmap(const ResTable& targetResTable,
            uint32_t targetCrc, uint32_t overlayCrc,
            const char* targetPath, const char* overlayPath,
            void** outData, size_t* outSize) const;

    static const size_t IDMAP_HEADER_SIZE_BYTES = 4 * sizeof(uint32_t) + 2 * 256;
    static const size_t IDMAP_CONSTRAINTS_COUNT_SIZE_BYTES = sizeof(uint32_t);

    // Retrieve idmap meta-data.
    //
    // This function only requires the idmap header (the first
    // IDMAP_HEADER_SIZE_BYTES) bytes of an idmap file.
    static bool getIdmapInfo(const void* idmap, size_t size,
            uint32_t* pVersion,
            uint32_t* pTargetCrc, uint32_t* pOverlayCrc,
            String8* pTargetPath, String8* pOverlayPath);

    void print(bool inclValues) const;
    static String8 normalizeForOutput(const char* input);

private:
    struct Header;
    struct Type;
    struct Entry;
    struct Package;
    struct PackageGroup;
    typedef Vector<Type*> TypeList;

    struct bag_set {
        size_t numAttrs;    // number in array
        size_t availAttrs;  // total space in array
        uint32_t typeSpecFlags;
        // Followed by 'numAttr' bag_entry structures.
    };

    /**
     * Configuration dependent cached data. This must be cleared when the configuration is
     * changed (setParameters).
     */
    struct TypeCacheEntry {
        TypeCacheEntry() : cachedBags(NULL) {}

        // Computed attribute bags for this type.
        bag_set** cachedBags;

        // Pre-filtered list of configurations (per asset path) that match the parameters set on this
        // ResTable.
        Vector<std::shared_ptr<Vector<const ResTable_type*>>> filteredConfigs;
    };

    status_t addInternal(const void* data, size_t size, const void* idmapData, size_t idmapDataSize,
            bool appAsLib, const int32_t cookie, bool copyData, bool isSystemAsset=false);

    ssize_t getResourcePackageIndex(uint32_t resID) const;
    ssize_t getResourcePackageIndexFromPackage(uint8_t packageID) const;

    status_t getEntry(
        const PackageGroup* packageGroup, int typeIndex, int entryIndex,
        const ResTable_config* config,
        Entry* outEntry) const;

    uint32_t findEntry(const PackageGroup* group, ssize_t typeIndex, const char16_t* name,
            size_t nameLen, uint32_t* outTypeSpecFlags) const;

    status_t parsePackage(
        const ResTable_package* const pkg, const Header* const header,
        bool appAsLib, bool isSystemAsset);

    void print_value(const Package* pkg, const Res_value& value) const;

    template <typename Func>
    void forEachConfiguration(bool ignoreMipmap, bool ignoreAndroidPackage,
                              bool includeSystemConfigs, const Func& f) const;

    mutable Mutex               mLock;

    // Mutex that controls access to the list of pre-filtered configurations
    // to check when looking up entries.
    // When iterating over a bag, the mLock mutex is locked. While mLock is locked,
    // we do resource lookups.
    // Mutex is not reentrant, so we must use a different lock than mLock.
    mutable Mutex               mFilteredConfigLock;

    status_t                    mError;

    ResTable_config             mParams;

    // Array of all resource tables.
    Vector<Header*>             mHeaders;

    // Array of packages in all resource tables.
    Vector<PackageGroup*>       mPackageGroups;

    // Mapping from resource package IDs to indices into the internal
    // package array.
    uint8_t                     mPackageMap[256];

    uint8_t                     mNextPackageId;
};

}   // namespace android

#endif // _LIBS_UTILS_RESOURCE_TYPES_H