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1 /*
2  * Copyright (C) 2017 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef INCIDENT_HELPER_UTIL_H
18 #define INCIDENT_HELPER_UTIL_H
19 
20 #include <map>
21 #include <stack>
22 #include <string>
23 #include <vector>
24 
25 #include <android/util/ProtoOutputStream.h>
26 
27 using namespace android::util;
28 
29 typedef std::vector<std::string> header_t;
30 typedef std::vector<std::string> record_t;
31 typedef std::string (*trans_func) (const std::string&);
32 
33 const std::string DEFAULT_WHITESPACE = " \t";
34 const std::string DEFAULT_NEWLINE = "\r\n";
35 const std::string TAB_DELIMITER = "\t";
36 const std::string COMMA_DELIMITER = ",";
37 const std::string PIPE_DELIMITER = "|";
38 const std::string PARENTHESES_DELIMITER = "()";
39 
40 // returns true if c is a-zA-Z0-9 or underscore
41 bool isValidChar(char c);
42 
43 // trim the string with the given charset
44 std::string trim(const std::string& s, const std::string& charset);
45 
46 /**
47  * When a text has a table format like this
48  * line 1: HeadA HeadB HeadC
49  * line 2: v1    v2    v3
50  * line 3: v11   v12   v13
51  *
52  * We want to parse the line in structure given the delimiter.
53  * parseHeader is used to parse the firse line of the table and returns a list of strings in lower case
54  * parseRecord is used to parse other lines and returns a list of strings
55  * empty strings are skipped
56  */
57 header_t parseHeader(const std::string& line, const std::string& delimiters = DEFAULT_WHITESPACE);
58 record_t parseRecord(const std::string& line, const std::string& delimiters = DEFAULT_WHITESPACE);
59 
60 /**
61  * Gets the list of end indices of each word in the line and places it in the given vector,
62  * clearing out the vector beforehand. These indices can be used with parseRecordByColumns.
63  * Will return false if there was a problem getting the indices. headerNames
64  * must be NULL terminated.
65  */
66 bool getColumnIndices(std::vector<int>& indices, const char* headerNames[], const std::string& line);
67 
68 /**
69  * When a text-format table aligns by its vertical position, it is not possible to split them by purely delimiters.
70  * This function allows to parse record by its header's column position' indices, must in ascending order.
71  * At the same time, it still looks at the char at index, if it doesn't belong to delimiters, moves forward to find the delimiters.
72  */
73 record_t parseRecordByColumns(const std::string& line, const std::vector<int>& indices, const std::string& delimiters = DEFAULT_WHITESPACE);
74 
75 /** Prints record_t to stderr */
76 void printRecord(const record_t& record);
77 
78 /**
79  * When the line starts/ends with the given key, the function returns true
80  * as well as the line argument is changed to the rest trimmed part of the original.
81  * e.g. "ZRAM: 6828K physical used for 31076K in swap (524284K total swap)" becomes
82  * "6828K physical used for 31076K in swap (524284K total swap)" when given key "ZRAM:",
83  * otherwise the line is not changed.
84  *
85  * In order to prevent two values have same prefix which cause entering to incorrect conditions,
86  * stripPrefix and stripSuffix can turn on a flag that requires the ending char in the line must not be a valid
87  * character or digits, this feature is off by default.
88  * i.e. ABC%some value, ABCD%other value
89  */
90 bool stripPrefix(std::string* line, const char* key, bool endAtDelimiter = false);
91 bool stripSuffix(std::string* line, const char* key, bool endAtDelimiter = false);
92 
93 /**
94  * behead the given line by the cut, return the head and reassign the line to be the rest.
95  */
96 std::string behead(std::string* line, const char cut);
97 
98 /**
99  * Converts string to the desired type
100  */
101 int toInt(const std::string& s);
102 long long toLongLong(const std::string& s);
103 double toDouble(const std::string& s);
104 
105 /**
106  * Reader class reads data from given fd in streaming fashion.
107  * The buffer size is controlled by capacity parameter.
108  */
109 class Reader
110 {
111 public:
112     explicit Reader(const int fd);
113     ~Reader();
114 
115     bool readLine(std::string* line);
116     bool ok(std::string* error);
117 
118 private:
119     FILE* mFile;
120     char* mBuffer;
121     std::string mStatus;
122 };
123 
124 /**
125  * The Table class is constructed from two arrays generated by the given message with
126  * option (stream_proto.stream_msg).enable_fields_mapping = true.
127  * The names are each field's names in the message and must corresponding to the header/name of
128  * the text to be parsed, and the ids are the streaming proto encoded field ids.
129  *
130  * This class then allows users to insert the table values to proto based on its header.
131  *
132  * Advance feature: if some fields in the message are enums, user must explicitly add the
133  * mapping from enum name string to its enum values.
134  */
135 class Message;
136 class Table
137 {
138 friend class Message;
139 public:
140     Table(const char* names[], const uint64_t ids[], const int count);
141     ~Table();
142 
143     // Add enum names to values for parsing purpose.
144     void addEnumTypeMap(const char* field, const char* enumNames[], const int enumValues[], const int enumSize);
145 
146     // Manually add enum names to values mapping, useful when an Enum type is used by
147     // a number of fields, there must not be any enum name conflicts.
148     void addEnumNameToValue(const char* enumName, const int enumValue);
149 
150     // Based on given name, find the right field id, parse the text value and insert to proto.
151     // Return false if the given name can't be found.
152     bool insertField(ProtoOutputStream* proto, const std::string& name, const std::string& value);
153 private:
154     std::map<std::string, uint64_t> mFields;
155     std::map<std::string, std::map<std::string, int>> mEnums;
156     std::map<std::string, int> mEnumValuesByName;
157 };
158 
159 /**
160  * Reconstructs a typical proto message given its message Table, adds submessage fields explicitly.
161  * It allows user to insert nested proto values purely by the names. See insertField for detail.
162  */
163 class Message
164 {
165 public:
166     explicit Message(Table* table);
167     ~Message();
168 
169     // Reconstructs the typical proto message by adding its message fields.
170     void addSubMessage(uint64_t fieldId, Message* fieldMsg);
171 
172     // Inserts value if the given name has the corresponding field in its message and return true.
173     // It will recursively search the name in submessages and find the correct field to insert.
174     // For example, when the name is dalvik_vm_heapsize, and the message's corresponding proto is:
175     //     message Properties {
176     //         message DalvikVm {
177     //             int32 heapsize = 1;
178     //             bool  usejit = 2;
179     //         }
180     //         DalvikVm dalvik_vm = 1;
181     //         string hack_in = 2;
182     //     }
183     // The value will be inserted into field heapsize in dalvik_vm submessage.
184     //
185     // Also value belongs to same submessage MUST be inserted contiguously.
186     // For example, dalvik_vm_usejit must be inserted directly after dalvik_vm_heapsize, otherwise
187     // if hack_in attempts to be inserted before dalvik_vm_usejit, value of usejit isn't added as expected.
188     bool insertField(ProtoOutputStream* proto, const std::string& name, const std::string& value);
189 
190     // Starts a new message field proto session.
191     void startSession(ProtoOutputStream* proto, const std::string& name);
192 
193     // Ends the previous message field proto session.
194     void endSession(ProtoOutputStream* proto);
195 private:
196     Table* mTable;
197     std::string mPreviousField;
198     std::stack<uint64_t> mTokens;
199     std::map<std::string, Message*> mSubMessages;
200 };
201 
202 #endif  // INCIDENT_HELPER_UTIL_H
203