/*
 * Copyright (C) 2015 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.
 */

#include "record_file.h"

#include <fcntl.h>
#include <string.h>
#include <set>
#include <vector>

#include <android-base/logging.h>

#include "event_attr.h"
#include "record.h"
#include "system/extras/simpleperf/record_file.pb.h"
#include "utils.h"

namespace simpleperf {

using namespace PerfFileFormat;

namespace PerfFileFormat {

static const std::map<int, std::string> feature_name_map = {
    {FEAT_TRACING_DATA, "tracing_data"},
    {FEAT_BUILD_ID, "build_id"},
    {FEAT_HOSTNAME, "hostname"},
    {FEAT_OSRELEASE, "osrelease"},
    {FEAT_VERSION, "version"},
    {FEAT_ARCH, "arch"},
    {FEAT_NRCPUS, "nrcpus"},
    {FEAT_CPUDESC, "cpudesc"},
    {FEAT_CPUID, "cpuid"},
    {FEAT_TOTAL_MEM, "total_mem"},
    {FEAT_CMDLINE, "cmdline"},
    {FEAT_EVENT_DESC, "event_desc"},
    {FEAT_CPU_TOPOLOGY, "cpu_topology"},
    {FEAT_NUMA_TOPOLOGY, "numa_topology"},
    {FEAT_BRANCH_STACK, "branch_stack"},
    {FEAT_PMU_MAPPINGS, "pmu_mappings"},
    {FEAT_GROUP_DESC, "group_desc"},
    {FEAT_AUXTRACE, "auxtrace"},
    {FEAT_FILE, "file"},
    {FEAT_META_INFO, "meta_info"},
    {FEAT_DEBUG_UNWIND, "debug_unwind"},
    {FEAT_DEBUG_UNWIND_FILE, "debug_unwind_file"},
};

std::string GetFeatureName(int feature_id) {
  auto it = feature_name_map.find(feature_id);
  return it == feature_name_map.end() ? "" : it->second;
}

int GetFeatureId(const std::string& feature_name) {
  for (auto& pair : feature_name_map) {
    if (pair.second == feature_name) {
      return pair.first;
    }
  }
  return -1;
}

}  // namespace PerfFileFormat

std::unique_ptr<RecordFileReader> RecordFileReader::CreateInstance(const std::string& filename) {
  std::string mode = std::string("rb") + CLOSE_ON_EXEC_MODE;
  FILE* fp = fopen(filename.c_str(), mode.c_str());
  if (fp == nullptr) {
    PLOG(ERROR) << "failed to open record file '" << filename << "'";
    return nullptr;
  }
  auto reader = std::unique_ptr<RecordFileReader>(new RecordFileReader(filename, fp));
  if (!reader->ReadHeader() || !reader->ReadAttrSection() ||
      !reader->ReadFeatureSectionDescriptors() || !reader->ReadMetaInfoFeature()) {
    return nullptr;
  }
  reader->UseRecordingEnvironment();
  return reader;
}

RecordFileReader::RecordFileReader(const std::string& filename, FILE* fp)
    : filename_(filename),
      record_fp_(fp),
      event_id_pos_in_sample_records_(0),
      event_id_reverse_pos_in_non_sample_records_(0),
      read_record_size_(0) {}

RecordFileReader::~RecordFileReader() {
  if (record_fp_ != nullptr) {
    Close();
  }
}

bool RecordFileReader::Close() {
  bool result = true;
  if (fclose(record_fp_) != 0) {
    PLOG(ERROR) << "failed to close record file '" << filename_ << "'";
    result = false;
  }
  record_fp_ = nullptr;
  return result;
}

bool RecordFileReader::ReadHeader() {
  if (!Read(&header_, sizeof(header_))) {
    return false;
  }
  if (memcmp(header_.magic, PERF_MAGIC, sizeof(header_.magic)) != 0) {
    LOG(ERROR) << filename_ << " is not a valid profiling record file.";
    return false;
  }
  return true;
}

bool RecordFileReader::ReadAttrSection() {
  size_t attr_count = header_.attrs.size / header_.attr_size;
  if (header_.attr_size != sizeof(FileAttr)) {
    LOG(DEBUG) << "attr size (" << header_.attr_size << ") in " << filename_
               << " doesn't match expected size (" << sizeof(FileAttr) << ")";
  }
  if (attr_count == 0) {
    LOG(ERROR) << "no attr in file " << filename_;
    return false;
  }
  if (fseek(record_fp_, header_.attrs.offset, SEEK_SET) != 0) {
    PLOG(ERROR) << "fseek() failed";
    return false;
  }
  for (size_t i = 0; i < attr_count; ++i) {
    std::vector<char> buf(header_.attr_size);
    if (!Read(buf.data(), buf.size())) {
      return false;
    }
    // The size of perf_event_attr is changing between different linux kernel versions.
    // Make sure we copy correct data to memory.
    FileAttr attr;
    memset(&attr, 0, sizeof(attr));
    size_t section_desc_size = sizeof(attr.ids);
    size_t perf_event_attr_size = header_.attr_size - section_desc_size;
    memcpy(&attr.attr, &buf[0], std::min(sizeof(attr.attr), perf_event_attr_size));
    memcpy(&attr.ids, &buf[perf_event_attr_size], section_desc_size);
    file_attrs_.push_back(attr);
  }
  if (file_attrs_.size() > 1) {
    std::vector<perf_event_attr> attrs;
    for (const auto& file_attr : file_attrs_) {
      attrs.push_back(file_attr.attr);
    }
    if (!GetCommonEventIdPositionsForAttrs(attrs, &event_id_pos_in_sample_records_,
                                           &event_id_reverse_pos_in_non_sample_records_)) {
      return false;
    }
  }
  for (size_t i = 0; i < file_attrs_.size(); ++i) {
    std::vector<uint64_t> ids;
    if (!ReadIdsForAttr(file_attrs_[i], &ids)) {
      return false;
    }
    event_ids_for_file_attrs_.push_back(ids);
    for (auto id : ids) {
      event_id_to_attr_map_[id] = i;
    }
  }
  return true;
}

bool RecordFileReader::ReadFeatureSectionDescriptors() {
  std::vector<int> features;
  for (size_t i = 0; i < sizeof(header_.features); ++i) {
    for (size_t j = 0; j < 8; ++j) {
      if (header_.features[i] & (1 << j)) {
        features.push_back(i * 8 + j);
      }
    }
  }
  uint64_t feature_section_offset = header_.data.offset + header_.data.size;
  if (fseek(record_fp_, feature_section_offset, SEEK_SET) != 0) {
    PLOG(ERROR) << "fseek() failed";
    return false;
  }
  for (const auto& id : features) {
    SectionDesc desc;
    if (!Read(&desc, sizeof(desc))) {
      return false;
    }
    feature_section_descriptors_.emplace(id, desc);
  }
  return true;
}

bool RecordFileReader::ReadIdsForAttr(const FileAttr& attr, std::vector<uint64_t>* ids) {
  size_t id_count = attr.ids.size / sizeof(uint64_t);
  if (fseek(record_fp_, attr.ids.offset, SEEK_SET) != 0) {
    PLOG(ERROR) << "fseek() failed";
    return false;
  }
  ids->resize(id_count);
  if (!Read(ids->data(), attr.ids.size)) {
    return false;
  }
  return true;
}

void RecordFileReader::UseRecordingEnvironment() {
  std::string arch = ReadFeatureString(FEAT_ARCH);
  if (!arch.empty()) {
    scoped_arch_.reset(new ScopedCurrentArch(GetArchType(arch)));
  }
  auto& meta_info = GetMetaInfoFeature();
  if (auto it = meta_info.find("event_type_info"); it != meta_info.end()) {
    if (EventTypeManager::Instance().GetScopedFinder() == nullptr) {
      scoped_event_types_.reset(new ScopedEventTypes(it->second));
    }
  }
}

bool RecordFileReader::ReadDataSection(
    const std::function<bool(std::unique_ptr<Record>)>& callback) {
  std::unique_ptr<Record> record;
  while (ReadRecord(record)) {
    if (record == nullptr) {
      return true;
    }
    if (!callback(std::move(record))) {
      return false;
    }
  }
  return false;
}

bool RecordFileReader::ReadRecord(std::unique_ptr<Record>& record) {
  if (read_record_size_ == 0) {
    if (fseek(record_fp_, header_.data.offset, SEEK_SET) != 0) {
      PLOG(ERROR) << "fseek() failed";
      return false;
    }
  }
  record = nullptr;
  if (read_record_size_ < header_.data.size) {
    record = ReadRecord();
    if (record == nullptr) {
      return false;
    }
    if (record->type() == SIMPLE_PERF_RECORD_EVENT_ID) {
      ProcessEventIdRecord(*static_cast<EventIdRecord*>(record.get()));
    }
  }
  return true;
}

std::unique_ptr<Record> RecordFileReader::ReadRecord() {
  char header_buf[Record::header_size()];
  if (!Read(header_buf, Record::header_size())) {
    return nullptr;
  }
  RecordHeader header(header_buf);
  std::unique_ptr<char[]> p;
  if (header.type == SIMPLE_PERF_RECORD_SPLIT) {
    // Read until meeting a RECORD_SPLIT_END record.
    std::vector<char> buf;
    size_t cur_size = 0;
    char header_buf[Record::header_size()];
    while (header.type == SIMPLE_PERF_RECORD_SPLIT) {
      size_t bytes_to_read = header.size - Record::header_size();
      buf.resize(cur_size + bytes_to_read);
      if (!Read(&buf[cur_size], bytes_to_read)) {
        return nullptr;
      }
      cur_size += bytes_to_read;
      read_record_size_ += header.size;
      if (!Read(header_buf, Record::header_size())) {
        return nullptr;
      }
      header = RecordHeader(header_buf);
    }
    if (header.type != SIMPLE_PERF_RECORD_SPLIT_END) {
      LOG(ERROR) << "SPLIT records are not followed by a SPLIT_END record.";
      return nullptr;
    }
    read_record_size_ += header.size;
    header = RecordHeader(buf.data());
    p.reset(new char[header.size]);
    memcpy(p.get(), buf.data(), buf.size());
  } else {
    p.reset(new char[header.size]);
    memcpy(p.get(), header_buf, Record::header_size());
    if (header.size > Record::header_size()) {
      if (!Read(p.get() + Record::header_size(), header.size - Record::header_size())) {
        return nullptr;
      }
    }
    read_record_size_ += header.size;
  }

  const perf_event_attr* attr = &file_attrs_[0].attr;
  if (file_attrs_.size() > 1 && header.type < PERF_RECORD_USER_DEFINED_TYPE_START) {
    bool has_event_id = false;
    uint64_t event_id;
    if (header.type == PERF_RECORD_SAMPLE) {
      if (header.size > event_id_pos_in_sample_records_ + sizeof(uint64_t)) {
        has_event_id = true;
        event_id = *reinterpret_cast<uint64_t*>(p.get() + event_id_pos_in_sample_records_);
      }
    } else {
      if (header.size > event_id_reverse_pos_in_non_sample_records_) {
        has_event_id = true;
        event_id = *reinterpret_cast<uint64_t*>(p.get() + header.size -
                                                event_id_reverse_pos_in_non_sample_records_);
      }
    }
    if (has_event_id) {
      auto it = event_id_to_attr_map_.find(event_id);
      if (it != event_id_to_attr_map_.end()) {
        attr = &file_attrs_[it->second].attr;
      }
    }
  }
  auto r = ReadRecordFromOwnedBuffer(*attr, header.type, p.release());
  if (r->type() == PERF_RECORD_AUXTRACE) {
    auto auxtrace = static_cast<AuxTraceRecord*>(r.get());
    auxtrace->location.file_offset = header_.data.offset + read_record_size_;
    read_record_size_ += auxtrace->data->aux_size;
    if (fseek(record_fp_, auxtrace->data->aux_size, SEEK_CUR) != 0) {
      PLOG(ERROR) << "fseek() failed";
      return nullptr;
    }
  }
  return r;
}

bool RecordFileReader::Read(void* buf, size_t len) {
  if (len != 0 && fread(buf, len, 1, record_fp_) != 1) {
    PLOG(FATAL) << "failed to read file " << filename_;
    return false;
  }
  return true;
}

bool RecordFileReader::ReadAtOffset(uint64_t offset, void* buf, size_t len) {
  if (fseek(record_fp_, offset, SEEK_SET) != 0) {
    PLOG(ERROR) << "failed to seek to " << offset;
    return false;
  }
  return Read(buf, len);
}

void RecordFileReader::ProcessEventIdRecord(const EventIdRecord& r) {
  for (size_t i = 0; i < r.count; ++i) {
    event_ids_for_file_attrs_[r.data[i].attr_id].push_back(r.data[i].event_id);
    event_id_to_attr_map_[r.data[i].event_id] = r.data[i].attr_id;
  }
}

size_t RecordFileReader::GetAttrIndexOfRecord(const Record* record) {
  auto it = event_id_to_attr_map_.find(record->Id());
  if (it != event_id_to_attr_map_.end()) {
    return it->second;
  }
  return 0;
}

bool RecordFileReader::ReadFeatureSection(int feature, std::vector<char>* data) {
  const std::map<int, SectionDesc>& section_map = FeatureSectionDescriptors();
  auto it = section_map.find(feature);
  if (it == section_map.end()) {
    return false;
  }
  SectionDesc section = it->second;
  data->resize(section.size);
  if (section.size == 0) {
    return true;
  }
  if (!ReadAtOffset(section.offset, data->data(), data->size())) {
    return false;
  }
  return true;
}

bool RecordFileReader::ReadFeatureSection(int feature, std::string* data) {
  const std::map<int, SectionDesc>& section_map = FeatureSectionDescriptors();
  auto it = section_map.find(feature);
  if (it == section_map.end()) {
    return false;
  }
  SectionDesc section = it->second;
  data->resize(section.size);
  if (section.size == 0) {
    return true;
  }
  if (!ReadAtOffset(section.offset, data->data(), data->size())) {
    return false;
  }
  return true;
}

std::vector<std::string> RecordFileReader::ReadCmdlineFeature() {
  std::vector<char> buf;
  if (!ReadFeatureSection(FEAT_CMDLINE, &buf)) {
    return std::vector<std::string>();
  }
  const char* p = buf.data();
  const char* end = buf.data() + buf.size();
  std::vector<std::string> cmdline;
  uint32_t arg_count;
  MoveFromBinaryFormat(arg_count, p);
  CHECK_LE(p, end);
  for (size_t i = 0; i < arg_count; ++i) {
    uint32_t len;
    MoveFromBinaryFormat(len, p);
    CHECK_LE(p + len, end);
    cmdline.push_back(p);
    p += len;
  }
  return cmdline;
}

std::vector<BuildIdRecord> RecordFileReader::ReadBuildIdFeature() {
  std::vector<char> buf;
  if (!ReadFeatureSection(FEAT_BUILD_ID, &buf)) {
    return std::vector<BuildIdRecord>();
  }
  const char* p = buf.data();
  const char* end = buf.data() + buf.size();
  std::vector<BuildIdRecord> result;
  while (p < end) {
    auto header = reinterpret_cast<const perf_event_header*>(p);
    CHECK_LE(p + header->size, end);
    char* binary = new char[header->size];
    memcpy(binary, p, header->size);
    p += header->size;
    BuildIdRecord record(binary);
    record.OwnBinary();
    // Set type explicitly as the perf.data produced by perf doesn't set it.
    record.SetTypeAndMisc(PERF_RECORD_BUILD_ID, record.misc());
    result.push_back(std::move(record));
  }
  return result;
}

std::string RecordFileReader::ReadFeatureString(int feature) {
  std::vector<char> buf;
  if (!ReadFeatureSection(feature, &buf)) {
    return std::string();
  }
  const char* p = buf.data();
  const char* end = buf.data() + buf.size();
  uint32_t len;
  MoveFromBinaryFormat(len, p);
  CHECK_LE(p + len, end);
  return p;
}

std::vector<uint64_t> RecordFileReader::ReadAuxTraceFeature() {
  std::vector<char> buf;
  if (!ReadFeatureSection(FEAT_AUXTRACE, &buf)) {
    return {};
  }
  std::vector<uint64_t> auxtrace_offset;
  const char* p = buf.data();
  const char* end = buf.data() + buf.size();
  if (buf.size() / sizeof(uint64_t) % 2 == 1) {
    // Recording files generated by linux perf contain an extra uint64 field. Skip it here.
    p += sizeof(uint64_t);
  }
  while (p < end) {
    uint64_t offset;
    uint64_t size;
    MoveFromBinaryFormat(offset, p);
    auxtrace_offset.push_back(offset);
    MoveFromBinaryFormat(size, p);
    CHECK_EQ(size, AuxTraceRecord::Size());
  }
  return auxtrace_offset;
}

bool RecordFileReader::ReadFileFeature(size_t& read_pos, FileFeature* file) {
  auto it = feature_section_descriptors_.find(FEAT_FILE);
  if (it == feature_section_descriptors_.end()) {
    return false;
  }
  if (read_pos >= it->second.size) {
    return false;
  }
  if (read_pos == 0) {
    if (fseek(record_fp_, it->second.offset, SEEK_SET) != 0) {
      PLOG(ERROR) << "fseek() failed";
      return false;
    }
  }
  uint32_t size;
  if (!Read(&size, 4)) {
    return false;
  }
  std::vector<char> buf(size);
  if (!Read(buf.data(), size)) {
    return false;
  }
  read_pos += 4 + size;
  const char* p = buf.data();
  file->path = p;
  p += file->path.size() + 1;
  uint32_t file_type;
  MoveFromBinaryFormat(file_type, p);
  if (file_type > DSO_UNKNOWN_FILE) {
    LOG(ERROR) << "unknown file type for " << file->path
               << " in file feature section: " << file_type;
    return false;
  }
  file->type = static_cast<DsoType>(file_type);
  MoveFromBinaryFormat(file->min_vaddr, p);
  uint32_t symbol_count;
  MoveFromBinaryFormat(symbol_count, p);
  file->symbols.clear();
  file->symbols.reserve(symbol_count);
  for (uint32_t i = 0; i < symbol_count; ++i) {
    uint64_t start_vaddr;
    uint32_t len;
    MoveFromBinaryFormat(start_vaddr, p);
    MoveFromBinaryFormat(len, p);
    std::string name = p;
    p += name.size() + 1;
    file->symbols.emplace_back(name, start_vaddr, len);
  }
  file->dex_file_offsets.clear();
  if (file->type == DSO_DEX_FILE) {
    uint32_t offset_count;
    MoveFromBinaryFormat(offset_count, p);
    file->dex_file_offsets.resize(offset_count);
    MoveFromBinaryFormat(file->dex_file_offsets.data(), offset_count, p);
  }
  file->file_offset_of_min_vaddr = std::numeric_limits<uint64_t>::max();
  if ((file->type == DSO_ELF_FILE || file->type == DSO_KERNEL_MODULE) &&
      static_cast<size_t>(p - buf.data()) < size) {
    MoveFromBinaryFormat(file->file_offset_of_min_vaddr, p);
  }
  CHECK_EQ(size, static_cast<size_t>(p - buf.data()))
      << "file " << file->path << ", type " << file->type;
  return true;
}

bool RecordFileReader::ReadMetaInfoFeature() {
  if (feature_section_descriptors_.count(FEAT_META_INFO)) {
    std::vector<char> buf;
    if (!ReadFeatureSection(FEAT_META_INFO, &buf)) {
      return false;
    }
    const char* p = buf.data();
    const char* end = buf.data() + buf.size();
    while (p < end) {
      const char* key = p;
      const char* value = key + strlen(key) + 1;
      CHECK(value < end);
      meta_info_[p] = value;
      p = value + strlen(value) + 1;
    }
  }
  return true;
}

std::optional<DebugUnwindFeature> RecordFileReader::ReadDebugUnwindFeature() {
  if (feature_section_descriptors_.count(FEAT_DEBUG_UNWIND)) {
    std::string s;
    if (!ReadFeatureSection(FEAT_DEBUG_UNWIND, &s)) {
      return std::nullopt;
    }
    proto::DebugUnwindFeature proto_debug_unwind;
    proto_debug_unwind.ParseFromString(s);
    DebugUnwindFeature debug_unwind(proto_debug_unwind.file_size());
    for (size_t i = 0; i < proto_debug_unwind.file_size(); i++) {
      debug_unwind[i].path = proto_debug_unwind.file(i).path();
      debug_unwind[i].size = proto_debug_unwind.file(i).size();
    }
    return debug_unwind;
  }
  return std::nullopt;
}

void RecordFileReader::LoadBuildIdAndFileFeatures(ThreadTree& thread_tree) {
  std::vector<BuildIdRecord> records = ReadBuildIdFeature();
  std::vector<std::pair<std::string, BuildId>> build_ids;
  for (auto& r : records) {
    build_ids.push_back(std::make_pair(r.filename, r.build_id));
  }
  Dso::SetBuildIds(build_ids);

  if (HasFeature(PerfFileFormat::FEAT_FILE)) {
    FileFeature file_feature;
    size_t read_pos = 0;
    while (ReadFileFeature(read_pos, &file_feature)) {
      thread_tree.AddDsoInfo(file_feature);
    }
  }
}

bool RecordFileReader::ReadAuxData(uint32_t cpu, uint64_t aux_offset, void* buf, size_t size) {
  long saved_pos = ftell(record_fp_);
  if (saved_pos == -1) {
    PLOG(ERROR) << "ftell() failed";
    return false;
  }
  if (aux_data_location_.empty() && !BuildAuxDataLocation()) {
    return false;
  }
  AuxDataLocation* location = nullptr;
  auto it = aux_data_location_.find(cpu);
  if (it != aux_data_location_.end()) {
    auto comp = [](uint64_t aux_offset, const AuxDataLocation& location) {
      return aux_offset < location.aux_offset;
    };
    auto location_it = std::upper_bound(it->second.begin(), it->second.end(), aux_offset, comp);
    if (location_it != it->second.begin()) {
      --location_it;
      if (location_it->aux_offset + location_it->aux_size >= aux_offset + size) {
        location = &*location_it;
      }
    }
  }
  if (location == nullptr) {
    LOG(ERROR) << "failed to find file offset of aux data: cpu " << cpu << ", aux_offset "
               << aux_offset << ", size " << size;
    return false;
  }
  if (!ReadAtOffset(aux_offset - location->aux_offset + location->file_offset, buf, size)) {
    return false;
  }
  if (fseek(record_fp_, saved_pos, SEEK_SET) != 0) {
    PLOG(ERROR) << "fseek() failed";
    return false;
  }
  return true;
}

bool RecordFileReader::BuildAuxDataLocation() {
  std::vector<uint64_t> auxtrace_offset = ReadAuxTraceFeature();
  if (auxtrace_offset.empty()) {
    LOG(ERROR) << "failed to read auxtrace feature section";
    return false;
  }
  std::unique_ptr<char[]> buf(new char[AuxTraceRecord::Size()]);
  for (auto offset : auxtrace_offset) {
    if (!ReadAtOffset(offset, buf.get(), AuxTraceRecord::Size())) {
      return false;
    }
    AuxTraceRecord auxtrace(buf.get());
    aux_data_location_[auxtrace.data->cpu].emplace_back(
        auxtrace.data->offset, auxtrace.data->aux_size, offset + auxtrace.size());
  }
  return true;
}

std::vector<std::unique_ptr<Record>> RecordFileReader::DataSection() {
  std::vector<std::unique_ptr<Record>> records;
  ReadDataSection([&](std::unique_ptr<Record> record) {
    records.push_back(std::move(record));
    return true;
  });
  return records;
}

bool IsPerfDataFile(const std::string& filename) {
  auto fd = FileHelper::OpenReadOnly(filename);
  if (fd.ok()) {
    PerfFileFormat::FileHeader header;
    return android::base::ReadFully(fd, &header, sizeof(header)) &&
           memcmp(header.magic, PERF_MAGIC, sizeof(header.magic)) == 0;
  }
  return false;
}

}  // namespace simpleperf