/*
 * 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.h"

#include <inttypes.h>
#include <algorithm>
#include <unordered_map>

#include <android-base/logging.h>
#include <android-base/stringprintf.h>

#include "dso.h"
#include "environment.h"
#include "perf_regs.h"
#include "utils.h"

static std::string RecordTypeToString(int record_type) {
  static std::unordered_map<int, std::string> record_type_names = {
      {PERF_RECORD_MMAP, "mmap"},
      {PERF_RECORD_LOST, "lost"},
      {PERF_RECORD_COMM, "comm"},
      {PERF_RECORD_EXIT, "exit"},
      {PERF_RECORD_THROTTLE, "throttle"},
      {PERF_RECORD_UNTHROTTLE, "unthrottle"},
      {PERF_RECORD_FORK, "fork"},
      {PERF_RECORD_READ, "read"},
      {PERF_RECORD_SAMPLE, "sample"},
      {PERF_RECORD_BUILD_ID, "build_id"},
      {PERF_RECORD_MMAP2, "mmap2"},
      {SIMPLE_PERF_RECORD_KERNEL_SYMBOL, "kernel_symbol"},
      {SIMPLE_PERF_RECORD_DSO, "dso"},
      {SIMPLE_PERF_RECORD_SYMBOL, "symbol"},
  };

  auto it = record_type_names.find(record_type);
  if (it != record_type_names.end()) {
    return it->second;
  }
  return android::base::StringPrintf("unknown(%d)", record_type);
}

template <class T>
void MoveFromBinaryFormat(T* data_p, size_t n, const char*& p) {
  size_t size = n * sizeof(T);
  memcpy(data_p, p, size);
  p += size;
}

template <class T>
void MoveToBinaryFormat(const T& data, char*& p) {
  *reinterpret_cast<T*>(p) = data;
  p += sizeof(T);
}

template <class T>
void MoveToBinaryFormat(const T* data_p, size_t n, char*& p) {
  size_t size = n * sizeof(T);
  memcpy(p, data_p, size);
  p += size;
}

SampleId::SampleId() { memset(this, 0, sizeof(SampleId)); }

// Return sample_id size in binary format.
size_t SampleId::CreateContent(const perf_event_attr& attr, uint64_t event_id) {
  sample_id_all = attr.sample_id_all;
  sample_type = attr.sample_type;
  id_data.id = event_id;
  // Other data are not necessary. TODO: Set missing SampleId data.
  return Size();
}

void SampleId::ReadFromBinaryFormat(const perf_event_attr& attr, const char* p,
                                    const char* end) {
  sample_id_all = attr.sample_id_all;
  sample_type = attr.sample_type;
  if (sample_id_all) {
    if (sample_type & PERF_SAMPLE_TID) {
      MoveFromBinaryFormat(tid_data, p);
    }
    if (sample_type & PERF_SAMPLE_TIME) {
      MoveFromBinaryFormat(time_data, p);
    }
    if (sample_type & PERF_SAMPLE_ID) {
      MoveFromBinaryFormat(id_data, p);
    }
    if (sample_type & PERF_SAMPLE_STREAM_ID) {
      MoveFromBinaryFormat(stream_id_data, p);
    }
    if (sample_type & PERF_SAMPLE_CPU) {
      MoveFromBinaryFormat(cpu_data, p);
    }
    if (sample_type & PERF_SAMPLE_IDENTIFIER) {
      MoveFromBinaryFormat(id_data, p);
    }
  }
  CHECK_LE(p, end);
  if (p < end) {
    LOG(DEBUG) << "Record SampleId part has " << end - p << " bytes left\n";
  }
}

void SampleId::WriteToBinaryFormat(char*& p) const {
  if (sample_id_all) {
    if (sample_type & PERF_SAMPLE_TID) {
      MoveToBinaryFormat(tid_data, p);
    }
    if (sample_type & PERF_SAMPLE_TIME) {
      MoveToBinaryFormat(time_data, p);
    }
    if (sample_type & PERF_SAMPLE_ID) {
      MoveToBinaryFormat(id_data, p);
    }
    if (sample_type & PERF_SAMPLE_STREAM_ID) {
      MoveToBinaryFormat(stream_id_data, p);
    }
    if (sample_type & PERF_SAMPLE_CPU) {
      MoveToBinaryFormat(cpu_data, p);
    }
  }
}

void SampleId::Dump(size_t indent) const {
  if (sample_id_all) {
    if (sample_type & PERF_SAMPLE_TID) {
      PrintIndented(indent, "sample_id: pid %u, tid %u\n", tid_data.pid,
                    tid_data.tid);
    }
    if (sample_type & PERF_SAMPLE_TIME) {
      PrintIndented(indent, "sample_id: time %" PRId64 "\n", time_data.time);
    }
    if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) {
      PrintIndented(indent, "sample_id: id %" PRId64 "\n", id_data.id);
    }
    if (sample_type & PERF_SAMPLE_STREAM_ID) {
      PrintIndented(indent, "sample_id: stream_id %" PRId64 "\n",
                    stream_id_data.stream_id);
    }
    if (sample_type & PERF_SAMPLE_CPU) {
      PrintIndented(indent, "sample_id: cpu %u, res %u\n", cpu_data.cpu,
                    cpu_data.res);
    }
  }
}

size_t SampleId::Size() const {
  size_t size = 0;
  if (sample_id_all) {
    if (sample_type & PERF_SAMPLE_TID) {
      size += sizeof(PerfSampleTidType);
    }
    if (sample_type & PERF_SAMPLE_TIME) {
      size += sizeof(PerfSampleTimeType);
    }
    if (sample_type & PERF_SAMPLE_ID) {
      size += sizeof(PerfSampleIdType);
    }
    if (sample_type & PERF_SAMPLE_STREAM_ID) {
      size += sizeof(PerfSampleStreamIdType);
    }
    if (sample_type & PERF_SAMPLE_CPU) {
      size += sizeof(PerfSampleCpuType);
    }
    if (sample_type & PERF_SAMPLE_IDENTIFIER) {
      size += sizeof(PerfSampleIdType);
    }
  }
  return size;
}

void Record::Dump(size_t indent) const {
  PrintIndented(indent, "record %s: type %u, misc %u, size %u\n",
                RecordTypeToString(type()).c_str(), type(), misc(), size());
  DumpData(indent + 1);
  sample_id.Dump(indent + 1);
}

uint64_t Record::Timestamp() const { return sample_id.time_data.time; }

MmapRecord::MmapRecord(const perf_event_attr& attr,
                       const perf_event_header* pheader)
    : Record(pheader) {
  const char* p = reinterpret_cast<const char*>(pheader + 1);
  const char* end = reinterpret_cast<const char*>(pheader) + size();
  MoveFromBinaryFormat(data, p);
  filename = p;
  p += ALIGN(filename.size() + 1, 8);
  CHECK_LE(p, end);
  sample_id.ReadFromBinaryFormat(attr, p, end);
}

std::vector<char> MmapRecord::BinaryFormat() const {
  std::vector<char> buf(size());
  char* p = buf.data();
  MoveToBinaryFormat(header, p);
  MoveToBinaryFormat(data, p);
  strcpy(p, filename.c_str());
  p += ALIGN(filename.size() + 1, 8);
  sample_id.WriteToBinaryFormat(p);
  return buf;
}

void MmapRecord::AdjustSizeBasedOnData() {
  SetSize(header_size() + sizeof(data) + ALIGN(filename.size() + 1, 8) +
          sample_id.Size());
}

void MmapRecord::DumpData(size_t indent) const {
  PrintIndented(indent,
                "pid %u, tid %u, addr 0x%" PRIx64 ", len 0x%" PRIx64 "\n",
                data.pid, data.tid, data.addr, data.len);
  PrintIndented(indent, "pgoff 0x%" PRIx64 ", filename %s\n", data.pgoff,
                filename.c_str());
}

MmapRecord MmapRecord::Create(const perf_event_attr& attr, bool in_kernel,
                              uint32_t pid, uint32_t tid, uint64_t addr,
                              uint64_t len, uint64_t pgoff,
                              const std::string& filename, uint64_t event_id) {
  MmapRecord record;
  record.SetTypeAndMisc(PERF_RECORD_MMAP, in_kernel ? PERF_RECORD_MISC_KERNEL
                                                    : PERF_RECORD_MISC_USER);
  record.data.pid = pid;
  record.data.tid = tid;
  record.data.addr = addr;
  record.data.len = len;
  record.data.pgoff = pgoff;
  record.filename = filename;
  size_t sample_id_size = record.sample_id.CreateContent(attr, event_id);
  record.SetSize(record.header_size() + sizeof(record.data) +
                 ALIGN(record.filename.size() + 1, 8) + sample_id_size);
  return record;
}

Mmap2Record::Mmap2Record(const perf_event_attr& attr,
                         const perf_event_header* pheader)
    : Record(pheader) {
  const char* p = reinterpret_cast<const char*>(pheader + 1);
  const char* end = reinterpret_cast<const char*>(pheader) + size();
  MoveFromBinaryFormat(data, p);
  filename = p;
  p += ALIGN(filename.size() + 1, 8);
  CHECK_LE(p, end);
  sample_id.ReadFromBinaryFormat(attr, p, end);
}

std::vector<char> Mmap2Record::BinaryFormat() const {
  std::vector<char> buf(size());
  char* p = buf.data();
  MoveToBinaryFormat(header, p);
  MoveToBinaryFormat(data, p);
  strcpy(p, filename.c_str());
  p += ALIGN(filename.size() + 1, 8);
  sample_id.WriteToBinaryFormat(p);
  return buf;
}

void Mmap2Record::AdjustSizeBasedOnData() {
  SetSize(header_size() + sizeof(data) + ALIGN(filename.size() + 1, 8) +
          sample_id.Size());
}

void Mmap2Record::DumpData(size_t indent) const {
  PrintIndented(indent,
                "pid %u, tid %u, addr 0x%" PRIx64 ", len 0x%" PRIx64 "\n",
                data.pid, data.tid, data.addr, data.len);
  PrintIndented(indent, "pgoff 0x" PRIx64 ", maj %u, min %u, ino %" PRId64
                        ", ino_generation %" PRIu64 "\n",
                data.pgoff, data.maj, data.min, data.ino, data.ino_generation);
  PrintIndented(indent, "prot %u, flags %u, filenames %s\n", data.prot,
                data.flags, filename.c_str());
}

CommRecord::CommRecord(const perf_event_attr& attr,
                       const perf_event_header* pheader)
    : Record(pheader) {
  const char* p = reinterpret_cast<const char*>(pheader + 1);
  const char* end = reinterpret_cast<const char*>(pheader) + size();
  MoveFromBinaryFormat(data, p);
  comm = p;
  p += ALIGN(strlen(p) + 1, 8);
  CHECK_LE(p, end);
  sample_id.ReadFromBinaryFormat(attr, p, end);
}

std::vector<char> CommRecord::BinaryFormat() const {
  std::vector<char> buf(size());
  char* p = buf.data();
  MoveToBinaryFormat(header, p);
  MoveToBinaryFormat(data, p);
  strcpy(p, comm.c_str());
  p += ALIGN(comm.size() + 1, 8);
  sample_id.WriteToBinaryFormat(p);
  return buf;
}

void CommRecord::DumpData(size_t indent) const {
  PrintIndented(indent, "pid %u, tid %u, comm %s\n", data.pid, data.tid,
                comm.c_str());
}

CommRecord CommRecord::Create(const perf_event_attr& attr, uint32_t pid,
                              uint32_t tid, const std::string& comm,
                              uint64_t event_id) {
  CommRecord record;
  record.SetTypeAndMisc(PERF_RECORD_COMM, 0);
  record.data.pid = pid;
  record.data.tid = tid;
  record.comm = comm;
  size_t sample_id_size = record.sample_id.CreateContent(attr, event_id);
  record.SetSize(record.header_size() + sizeof(record.data) +
                 ALIGN(record.comm.size() + 1, 8) + sample_id_size);
  return record;
}

ExitOrForkRecord::ExitOrForkRecord(const perf_event_attr& attr,
                                   const perf_event_header* pheader)
    : Record(pheader) {
  const char* p = reinterpret_cast<const char*>(pheader + 1);
  const char* end = reinterpret_cast<const char*>(pheader) + size();
  MoveFromBinaryFormat(data, p);
  CHECK_LE(p, end);
  sample_id.ReadFromBinaryFormat(attr, p, end);
}

std::vector<char> ExitOrForkRecord::BinaryFormat() const {
  std::vector<char> buf(size());
  char* p = buf.data();
  MoveToBinaryFormat(header, p);
  MoveToBinaryFormat(data, p);
  sample_id.WriteToBinaryFormat(p);
  return buf;
}

void ExitOrForkRecord::DumpData(size_t indent) const {
  PrintIndented(indent, "pid %u, ppid %u, tid %u, ptid %u\n", data.pid,
                data.ppid, data.tid, data.ptid);
}

ForkRecord ForkRecord::Create(const perf_event_attr& attr, uint32_t pid,
                              uint32_t tid, uint32_t ppid, uint32_t ptid,
                              uint64_t event_id) {
  ForkRecord record;
  record.SetTypeAndMisc(PERF_RECORD_FORK, 0);
  record.data.pid = pid;
  record.data.ppid = ppid;
  record.data.tid = tid;
  record.data.ptid = ptid;
  record.data.time = 0;
  size_t sample_id_size = record.sample_id.CreateContent(attr, event_id);
  record.SetSize(record.header_size() + sizeof(record.data) + sample_id_size);
  return record;
}

SampleRecord::SampleRecord(const perf_event_attr& attr,
                           const perf_event_header* pheader)
    : Record(pheader) {
  const char* p = reinterpret_cast<const char*>(pheader + 1);
  const char* end = reinterpret_cast<const char*>(pheader) + size();
  sample_type = attr.sample_type;

  if (sample_type & PERF_SAMPLE_IDENTIFIER) {
    MoveFromBinaryFormat(id_data, p);
  }
  if (sample_type & PERF_SAMPLE_IP) {
    MoveFromBinaryFormat(ip_data, p);
  }
  if (sample_type & PERF_SAMPLE_TID) {
    MoveFromBinaryFormat(tid_data, p);
  }
  if (sample_type & PERF_SAMPLE_TIME) {
    MoveFromBinaryFormat(time_data, p);
  }
  if (sample_type & PERF_SAMPLE_ADDR) {
    MoveFromBinaryFormat(addr_data, p);
  }
  if (sample_type & PERF_SAMPLE_ID) {
    MoveFromBinaryFormat(id_data, p);
  }
  if (sample_type & PERF_SAMPLE_STREAM_ID) {
    MoveFromBinaryFormat(stream_id_data, p);
  }
  if (sample_type & PERF_SAMPLE_CPU) {
    MoveFromBinaryFormat(cpu_data, p);
  }
  if (sample_type & PERF_SAMPLE_PERIOD) {
    MoveFromBinaryFormat(period_data, p);
  }
  if (sample_type & PERF_SAMPLE_CALLCHAIN) {
    uint64_t nr;
    MoveFromBinaryFormat(nr, p);
    callchain_data.ips.resize(nr);
    MoveFromBinaryFormat(callchain_data.ips.data(), nr, p);
  }
  if (sample_type & PERF_SAMPLE_RAW) {
    uint32_t size;
    MoveFromBinaryFormat(size, p);
    raw_data.data.resize(size);
    MoveFromBinaryFormat(raw_data.data.data(), size, p);
  }
  if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
    uint64_t nr;
    MoveFromBinaryFormat(nr, p);
    branch_stack_data.stack.resize(nr);
    MoveFromBinaryFormat(branch_stack_data.stack.data(), nr, p);
  }
  if (sample_type & PERF_SAMPLE_REGS_USER) {
    MoveFromBinaryFormat(regs_user_data.abi, p);
    if (regs_user_data.abi == 0) {
      regs_user_data.reg_mask = 0;
    } else {
      regs_user_data.reg_mask = attr.sample_regs_user;
      size_t bit_nr = 0;
      for (size_t i = 0; i < 64; ++i) {
        if ((regs_user_data.reg_mask >> i) & 1) {
          bit_nr++;
        }
      }
      regs_user_data.regs.resize(bit_nr);
      MoveFromBinaryFormat(regs_user_data.regs.data(), bit_nr, p);
    }
  }
  if (sample_type & PERF_SAMPLE_STACK_USER) {
    uint64_t size;
    MoveFromBinaryFormat(size, p);
    if (size == 0) {
      stack_user_data.dyn_size = 0;
    } else {
      stack_user_data.data.resize(size);
      MoveFromBinaryFormat(stack_user_data.data.data(), size, p);
      MoveFromBinaryFormat(stack_user_data.dyn_size, p);
    }
  }
  // TODO: Add parsing of other PERF_SAMPLE_*.
  CHECK_LE(p, end);
  if (p < end) {
    LOG(DEBUG) << "Record has " << end - p << " bytes left\n";
  }
}

std::vector<char> SampleRecord::BinaryFormat() const {
  std::vector<char> buf(size());
  char* p = buf.data();
  MoveToBinaryFormat(header, p);
  if (sample_type & PERF_SAMPLE_IDENTIFIER) {
    MoveToBinaryFormat(id_data, p);
  }
  if (sample_type & PERF_SAMPLE_IP) {
    MoveToBinaryFormat(ip_data, p);
  }
  if (sample_type & PERF_SAMPLE_TID) {
    MoveToBinaryFormat(tid_data, p);
  }
  if (sample_type & PERF_SAMPLE_TIME) {
    MoveToBinaryFormat(time_data, p);
  }
  if (sample_type & PERF_SAMPLE_ADDR) {
    MoveToBinaryFormat(addr_data, p);
  }
  if (sample_type & PERF_SAMPLE_ID) {
    MoveToBinaryFormat(id_data, p);
  }
  if (sample_type & PERF_SAMPLE_STREAM_ID) {
    MoveToBinaryFormat(stream_id_data, p);
  }
  if (sample_type & PERF_SAMPLE_CPU) {
    MoveToBinaryFormat(cpu_data, p);
  }
  if (sample_type & PERF_SAMPLE_PERIOD) {
    MoveToBinaryFormat(period_data, p);
  }
  if (sample_type & PERF_SAMPLE_CALLCHAIN) {
    uint64_t nr = callchain_data.ips.size();
    MoveToBinaryFormat(nr, p);
    MoveToBinaryFormat(callchain_data.ips.data(), nr, p);
  }
  if (sample_type & PERF_SAMPLE_RAW) {
    uint32_t size = raw_data.data.size();
    MoveToBinaryFormat(size, p);
    MoveToBinaryFormat(raw_data.data.data(), size, p);
  }
  if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
    uint64_t nr = branch_stack_data.stack.size();
    MoveToBinaryFormat(nr, p);
    MoveToBinaryFormat(branch_stack_data.stack.data(), nr, p);
  }
  if (sample_type & PERF_SAMPLE_REGS_USER) {
    MoveToBinaryFormat(regs_user_data.abi, p);
    if (regs_user_data.abi != 0) {
      MoveToBinaryFormat(regs_user_data.regs.data(), regs_user_data.regs.size(),
                         p);
    }
  }
  if (sample_type & PERF_SAMPLE_STACK_USER) {
    uint64_t size = stack_user_data.data.size();
    MoveToBinaryFormat(size, p);
    if (size != 0) {
      MoveToBinaryFormat(stack_user_data.data.data(), size, p);
      MoveToBinaryFormat(stack_user_data.dyn_size, p);
    }
  }

  // If record command does stack unwinding, sample records' size may be
  // decreased. So we can't trust header.size here, and should adjust buffer
  // size based on real need.
  buf.resize(p - buf.data());
  return buf;
}

void SampleRecord::AdjustSizeBasedOnData() {
  size_t size = BinaryFormat().size();
  LOG(DEBUG) << "Record (type " << RecordTypeToString(type())
             << ") size is changed from " << this->size() << " to " << size;
  SetSize(size);
}

void SampleRecord::DumpData(size_t indent) const {
  PrintIndented(indent, "sample_type: 0x%" PRIx64 "\n", sample_type);
  if (sample_type & PERF_SAMPLE_IP) {
    PrintIndented(indent, "ip %p\n", reinterpret_cast<void*>(ip_data.ip));
  }
  if (sample_type & PERF_SAMPLE_TID) {
    PrintIndented(indent, "pid %u, tid %u\n", tid_data.pid, tid_data.tid);
  }
  if (sample_type & PERF_SAMPLE_TIME) {
    PrintIndented(indent, "time %" PRId64 "\n", time_data.time);
  }
  if (sample_type & PERF_SAMPLE_ADDR) {
    PrintIndented(indent, "addr %p\n", reinterpret_cast<void*>(addr_data.addr));
  }
  if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) {
    PrintIndented(indent, "id %" PRId64 "\n", id_data.id);
  }
  if (sample_type & PERF_SAMPLE_STREAM_ID) {
    PrintIndented(indent, "stream_id %" PRId64 "\n", stream_id_data.stream_id);
  }
  if (sample_type & PERF_SAMPLE_CPU) {
    PrintIndented(indent, "cpu %u, res %u\n", cpu_data.cpu, cpu_data.res);
  }
  if (sample_type & PERF_SAMPLE_PERIOD) {
    PrintIndented(indent, "period %" PRId64 "\n", period_data.period);
  }
  if (sample_type & PERF_SAMPLE_CALLCHAIN) {
    PrintIndented(indent, "callchain nr=%" PRIu64 "\n",
                  callchain_data.ips.size());
    for (auto& ip : callchain_data.ips) {
      PrintIndented(indent + 1, "0x%" PRIx64 "\n", ip);
    }
  }
  if (sample_type & PERF_SAMPLE_RAW) {
    PrintIndented(indent, "raw size=%zu\n", raw_data.data.size());
    const uint32_t* data =
        reinterpret_cast<const uint32_t*>(raw_data.data.data());
    size_t size = raw_data.data.size() / sizeof(uint32_t);
    for (size_t i = 0; i < size; ++i) {
      PrintIndented(indent + 1, "0x%08x (%zu)\n", data[i], data[i]);
    }
  }
  if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
    PrintIndented(indent, "branch_stack nr=%" PRIu64 "\n",
                  branch_stack_data.stack.size());
    for (auto& item : branch_stack_data.stack) {
      PrintIndented(indent + 1, "from 0x%" PRIx64 ", to 0x%" PRIx64
                                ", flags 0x%" PRIx64 "\n",
                    item.from, item.to, item.flags);
    }
  }
  if (sample_type & PERF_SAMPLE_REGS_USER) {
    PrintIndented(indent, "user regs: abi=%" PRId64 "\n", regs_user_data.abi);
    for (size_t i = 0, pos = 0; i < 64; ++i) {
      if ((regs_user_data.reg_mask >> i) & 1) {
        PrintIndented(
            indent + 1, "reg (%s) 0x%016" PRIx64 "\n",
            GetRegName(i, ScopedCurrentArch::GetCurrentArch()).c_str(),
            regs_user_data.regs[pos++]);
      }
    }
  }
  if (sample_type & PERF_SAMPLE_STACK_USER) {
    PrintIndented(indent, "user stack: size %zu dyn_size %" PRIu64 "\n",
                  stack_user_data.data.size(), stack_user_data.dyn_size);
    const uint64_t* p =
        reinterpret_cast<const uint64_t*>(stack_user_data.data.data());
    const uint64_t* end = p + (stack_user_data.data.size() / sizeof(uint64_t));
    while (p < end) {
      PrintIndented(indent + 1, "");
      for (size_t i = 0; i < 4 && p < end; ++i, ++p) {
        printf(" %016" PRIx64, *p);
      }
      printf("\n");
    }
    printf("\n");
  }
}

uint64_t SampleRecord::Timestamp() const { return time_data.time; }

BuildIdRecord::BuildIdRecord(const perf_event_header* pheader)
    : Record(pheader) {
  const char* p = reinterpret_cast<const char*>(pheader + 1);
  const char* end = reinterpret_cast<const char*>(pheader) + size();
  MoveFromBinaryFormat(pid, p);
  build_id = BuildId(p, BUILD_ID_SIZE);
  p += ALIGN(build_id.Size(), 8);
  filename = p;
  p += ALIGN(filename.size() + 1, 64);
  CHECK_EQ(p, end);
}

std::vector<char> BuildIdRecord::BinaryFormat() const {
  std::vector<char> buf(size());
  char* p = buf.data();
  MoveToBinaryFormat(header, p);
  MoveToBinaryFormat(pid, p);
  memcpy(p, build_id.Data(), build_id.Size());
  p += ALIGN(build_id.Size(), 8);
  strcpy(p, filename.c_str());
  return buf;
}

void BuildIdRecord::DumpData(size_t indent) const {
  PrintIndented(indent, "pid %u\n", pid);
  PrintIndented(indent, "build_id %s\n", build_id.ToString().c_str());
  PrintIndented(indent, "filename %s\n", filename.c_str());
}

BuildIdRecord BuildIdRecord::Create(bool in_kernel, pid_t pid,
                                    const BuildId& build_id,
                                    const std::string& filename) {
  BuildIdRecord record;
  record.SetTypeAndMisc(PERF_RECORD_BUILD_ID, in_kernel
                                                  ? PERF_RECORD_MISC_KERNEL
                                                  : PERF_RECORD_MISC_USER);
  record.pid = pid;
  record.build_id = build_id;
  record.filename = filename;
  record.SetSize(record.header_size() + sizeof(record.pid) +
                 ALIGN(record.build_id.Size(), 8) +
                 ALIGN(filename.size() + 1, 64));
  return record;
}

KernelSymbolRecord::KernelSymbolRecord(const perf_event_header* pheader)
    : Record(pheader) {
  const char* p = reinterpret_cast<const char*>(pheader + 1);
  const char* end = reinterpret_cast<const char*>(pheader) + size();
  uint32_t end_flag;
  MoveFromBinaryFormat(end_flag, p);
  end_of_symbols = (end_flag == 1);
  uint32_t size;
  MoveFromBinaryFormat(size, p);
  kallsyms.resize(size);
  if (size != 0u) {
    memcpy(&kallsyms[0], p, size);
  }
  p += ALIGN(size, 8);
  CHECK_EQ(p, end);
}

std::vector<char> KernelSymbolRecord::BinaryFormat() const {
  std::vector<char> buf(size());
  char* p = buf.data();
  MoveToBinaryFormat(header, p);
  uint32_t end_flag = (end_of_symbols ? 1 : 0);
  MoveToBinaryFormat(end_flag, p);
  uint32_t size = static_cast<uint32_t>(kallsyms.size());
  MoveToBinaryFormat(size, p);
  memcpy(p, kallsyms.data(), size);
  return buf;
}

void KernelSymbolRecord::DumpData(size_t indent) const {
  PrintIndented(indent, "end_of_symbols: %s\n",
                end_of_symbols ? "true" : "false");
  PrintIndented(indent, "kallsyms: %s\n", kallsyms.c_str());
}

std::vector<KernelSymbolRecord> KernelSymbolRecord::Create(
    const std::string& kallsyms) {
  std::vector<KernelSymbolRecord> result;
  size_t left_bytes = kallsyms.size();
  const size_t max_bytes_per_record = 64000;
  const char* p = kallsyms.c_str();
  while (left_bytes > 0) {
    size_t used_bytes = std::min(left_bytes, max_bytes_per_record);
    KernelSymbolRecord r;
    r.SetTypeAndMisc(SIMPLE_PERF_RECORD_KERNEL_SYMBOL, 0);
    r.end_of_symbols = (used_bytes == left_bytes);
    r.kallsyms.assign(p, used_bytes);
    r.SetSize(r.header_size() + 8 + ALIGN(r.kallsyms.size(), 8));
    result.push_back(r);
    p += used_bytes;
    left_bytes -= used_bytes;
  }
  return result;
}

DsoRecord::DsoRecord(const perf_event_header* pheader) : Record(pheader) {
  const char* p = reinterpret_cast<const char*>(pheader + 1);
  const char* end = reinterpret_cast<const char*>(pheader) + size();
  MoveFromBinaryFormat(dso_type, p);
  MoveFromBinaryFormat(dso_id, p);
  dso_name = p;
  p += ALIGN(dso_name.size() + 1, 8);
  CHECK_EQ(p, end);
}

std::vector<char> DsoRecord::BinaryFormat() const {
  std::vector<char> buf(size());
  char* p = buf.data();
  MoveToBinaryFormat(header, p);
  MoveToBinaryFormat(dso_type, p);
  MoveToBinaryFormat(dso_id, p);
  strcpy(p, dso_name.c_str());
  return buf;
}

void DsoRecord::DumpData(size_t indent) const {
  PrintIndented(indent, "dso_type: %s(%" PRIu64 ")\n",
                DsoTypeToString(static_cast<DsoType>(dso_type)), dso_type);
  PrintIndented(indent, "dso_id: %" PRIu64 "\n", dso_id);
  PrintIndented(indent, "dso_name: %s\n", dso_name.c_str());
}

DsoRecord DsoRecord::Create(uint64_t dso_type, uint64_t dso_id,
                            const std::string& dso_name) {
  DsoRecord record;
  record.SetTypeAndMisc(SIMPLE_PERF_RECORD_DSO, 0);
  record.dso_type = dso_type;
  record.dso_id = dso_id;
  record.dso_name = dso_name;
  record.SetSize(record.header_size() + 2 * sizeof(uint64_t) +
                 ALIGN(record.dso_name.size() + 1, 8));
  return record;
}

SymbolRecord::SymbolRecord(const perf_event_header* pheader) : Record(pheader) {
  const char* p = reinterpret_cast<const char*>(pheader + 1);
  const char* end = reinterpret_cast<const char*>(pheader) + size();
  MoveFromBinaryFormat(addr, p);
  MoveFromBinaryFormat(len, p);
  MoveFromBinaryFormat(dso_id, p);
  name = p;
  p += ALIGN(name.size() + 1, 8);
  CHECK_EQ(p, end);
}

std::vector<char> SymbolRecord::BinaryFormat() const {
  std::vector<char> buf(size());
  char* p = buf.data();
  MoveToBinaryFormat(header, p);
  MoveToBinaryFormat(addr, p);
  MoveToBinaryFormat(len, p);
  MoveToBinaryFormat(dso_id, p);
  strcpy(p, name.c_str());
  return buf;
}

void SymbolRecord::DumpData(size_t indent) const {
  PrintIndented(indent, "name: %s\n", name.c_str());
  PrintIndented(indent, "addr: 0x%" PRIx64 "\n", addr);
  PrintIndented(indent, "len: 0x%" PRIx64 "\n", len);
  PrintIndented(indent, "dso_id: %" PRIu64 "\n", dso_id);
}

SymbolRecord SymbolRecord::Create(uint64_t addr, uint64_t len,
                                  const std::string& name, uint64_t dso_id) {
  SymbolRecord record;
  record.SetTypeAndMisc(SIMPLE_PERF_RECORD_SYMBOL, 0);
  record.addr = addr;
  record.len = len;
  record.dso_id = dso_id;
  record.name = name;
  record.SetSize(record.header_size() + 3 * sizeof(uint64_t) +
                 ALIGN(record.name.size() + 1, 8));
  return record;
}

UnknownRecord::UnknownRecord(const perf_event_header* pheader)
    : Record(pheader) {
  const char* p = reinterpret_cast<const char*>(pheader + 1);
  const char* end = reinterpret_cast<const char*>(pheader) + size();
  data.insert(data.end(), p, end);
}

std::vector<char> UnknownRecord::BinaryFormat() const {
  std::vector<char> buf(size());
  char* p = buf.data();
  MoveToBinaryFormat(header, p);
  MoveToBinaryFormat(data.data(), data.size(), p);
  return buf;
}

void UnknownRecord::DumpData(size_t) const {}

std::unique_ptr<Record> ReadRecordFromBuffer(const perf_event_attr& attr,
                                             const perf_event_header* pheader) {
  switch (pheader->type) {
    case PERF_RECORD_MMAP:
      return std::unique_ptr<Record>(new MmapRecord(attr, pheader));
    case PERF_RECORD_MMAP2:
      return std::unique_ptr<Record>(new Mmap2Record(attr, pheader));
    case PERF_RECORD_COMM:
      return std::unique_ptr<Record>(new CommRecord(attr, pheader));
    case PERF_RECORD_EXIT:
      return std::unique_ptr<Record>(new ExitRecord(attr, pheader));
    case PERF_RECORD_FORK:
      return std::unique_ptr<Record>(new ForkRecord(attr, pheader));
    case PERF_RECORD_SAMPLE:
      return std::unique_ptr<Record>(new SampleRecord(attr, pheader));
    case SIMPLE_PERF_RECORD_KERNEL_SYMBOL:
      return std::unique_ptr<Record>(new KernelSymbolRecord(pheader));
    case SIMPLE_PERF_RECORD_DSO:
      return std::unique_ptr<Record>(new DsoRecord(pheader));
    case SIMPLE_PERF_RECORD_SYMBOL:
      return std::unique_ptr<Record>(new SymbolRecord(pheader));
    default:
      return std::unique_ptr<Record>(new UnknownRecord(pheader));
  }
}

std::vector<std::unique_ptr<Record>> ReadRecordsFromBuffer(
    const perf_event_attr& attr, const char* buf, size_t buf_size) {
  std::vector<std::unique_ptr<Record>> result;
  const char* p = buf;
  const char* end = buf + buf_size;
  while (p < end) {
    const perf_event_header* header =
        reinterpret_cast<const perf_event_header*>(p);
    uint32_t size = header->size;
    CHECK_LE(p + size, end);
    CHECK_NE(0u, size);
    result.push_back(ReadRecordFromBuffer(attr, header));
    p += size;
  }
  return result;
}

bool RecordCache::RecordWithSeq::IsHappensBefore(
    const RecordWithSeq& other) const {
  bool is_sample = (record->type() == PERF_RECORD_SAMPLE);
  bool is_other_sample = (other.record->type() == PERF_RECORD_SAMPLE);
  uint64_t time = record->Timestamp();
  uint64_t other_time = other.record->Timestamp();
  // The record with smaller time happens first.
  if (time != other_time) {
    return time < other_time;
  }
  // If happening at the same time, make non-sample records before sample
  // records, because non-sample records may contain useful information to
  // parse sample records.
  if (is_sample != is_other_sample) {
    return is_sample ? false : true;
  }
  // Otherwise, use the same order as they enter the cache.
  return seq < other.seq;
}

bool RecordCache::RecordComparator::operator()(const RecordWithSeq& r1,
                                               const RecordWithSeq& r2) {
  return r2.IsHappensBefore(r1);
}

RecordCache::RecordCache(bool has_timestamp, size_t min_cache_size,
                         uint64_t min_time_diff_in_ns)
    : has_timestamp_(has_timestamp),
      min_cache_size_(min_cache_size),
      min_time_diff_in_ns_(min_time_diff_in_ns),
      last_time_(0),
      cur_seq_(0),
      queue_(RecordComparator()) {}

RecordCache::~RecordCache() { PopAll(); }

void RecordCache::Push(std::unique_ptr<Record> record) {
  if (has_timestamp_) {
    last_time_ = std::max(last_time_, record->Timestamp());
  }
  queue_.push(CreateRecordWithSeq(record.release()));
}

void RecordCache::Push(std::vector<std::unique_ptr<Record>> records) {
  for (auto& r : records) {
    queue_.push(CreateRecordWithSeq(r.release()));
  }
}

std::unique_ptr<Record> RecordCache::Pop() {
  if (queue_.size() < min_cache_size_) {
    return nullptr;
  }
  Record* r = queue_.top().record;
  if (has_timestamp_) {
    if (r->Timestamp() + min_time_diff_in_ns_ > last_time_) {
      return nullptr;
    }
  }
  queue_.pop();
  return std::unique_ptr<Record>(r);
}

std::vector<std::unique_ptr<Record>> RecordCache::PopAll() {
  std::vector<std::unique_ptr<Record>> result;
  while (!queue_.empty()) {
    result.emplace_back(queue_.top().record);
    queue_.pop();
  }
  return result;
}

RecordCache::RecordWithSeq RecordCache::CreateRecordWithSeq(Record* r) {
  RecordWithSeq result;
  result.seq = cur_seq_++;
  result.record = r;
  return result;
}