/*
 * Copyright (C) 2018 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 "tools/trace_to_text/utils.h"

#include <inttypes.h>
#include <stdio.h>

#include <memory>
#include <ostream>
#include <utility>

#include "perfetto/base/logging.h"
#include "perfetto/ext/base/string_splitter.h"
#include "perfetto/ext/traced/sys_stats_counters.h"
#include "protos/perfetto/trace/ftrace/ftrace_stats.pb.h"

#include "protos/perfetto/trace/trace.pb.h"
#include "protos/perfetto/trace/trace_packet.pb.h"

namespace perfetto {
namespace trace_to_text {
namespace {

using Iterator = trace_processor::TraceProcessor::Iterator;

constexpr const char* kQueryUnsymbolized =
    "select spm.name, spm.build_id, spf.rel_pc "
    "from stack_profile_frame spf "
    "join stack_profile_mapping spm "
    "on spf.mapping = spm.id "
    "where spm.build_id != '' and spf.symbol_set_id == 0";

constexpr size_t kCompressionBufferSize = 500 * 1024;

std::string FromHex(const char* str, size_t size) {
  if (size % 2) {
    PERFETTO_DFATAL_OR_ELOG("Failed to parse hex %s", str);
    return "";
  }
  std::string result(size / 2, '\0');
  for (size_t i = 0; i < size; i += 2) {
    char hex_byte[3];
    hex_byte[0] = str[i];
    hex_byte[1] = str[i + 1];
    hex_byte[2] = '\0';
    char* end;
    long int byte = strtol(hex_byte, &end, 16);
    if (*end != '\0') {
      PERFETTO_DFATAL_OR_ELOG("Failed to parse hex %s", str);
      return "";
    }
    result[i / 2] = static_cast<char>(byte);
  }
  return result;
}

std::string FromHex(const std::string& str) {
  return FromHex(str.c_str(), str.size());
}

using NameAndBuildIdPair = std::pair<std::string, std::string>;

std::map<NameAndBuildIdPair, std::vector<uint64_t>> GetUnsymbolizedFrames(
    trace_processor::TraceProcessor* tp) {
  std::map<std::pair<std::string, std::string>, std::vector<uint64_t>> res;
  Iterator it = tp->ExecuteQuery(kQueryUnsymbolized);
  while (it.Next()) {
    auto name_and_buildid =
        std::make_pair(it.Get(0).string_value, FromHex(it.Get(1).string_value));
    int64_t rel_pc = it.Get(2).long_value;
    res[name_and_buildid].emplace_back(rel_pc);
  }
  if (!it.Status().ok()) {
    PERFETTO_DFATAL_OR_ELOG("Invalid iterator: %s",
                            it.Status().message().c_str());
    return {};
  }
  return res;
}

}  // namespace

void ForEachPacketBlobInTrace(
    std::istream* input,
    const std::function<void(std::unique_ptr<char[]>, size_t)>& f) {
  size_t bytes_processed = 0;
  // The trace stream can be very large. We cannot just pass it in one go to
  // libprotobuf as that will refuse to parse messages > 64MB. However we know
  // that a trace is merely a sequence of TracePackets. Here we just manually
  // tokenize the repeated TracePacket messages and parse them individually
  // using libprotobuf.
  for (uint32_t i = 0;; i++) {
    if ((i & 0x3f) == 0) {
      fprintf(stderr, "Processing trace: %8zu KB%c", bytes_processed / 1024,
              kProgressChar);
      fflush(stderr);
    }
    // A TracePacket consists in one byte stating its field id and type ...
    char preamble;
    input->get(preamble);
    if (!input->good())
      break;
    bytes_processed++;
    PERFETTO_DCHECK(preamble == 0x0a);  // Field ID:1, type:length delimited.

    // ... a varint stating its size ...
    uint32_t field_size = 0;
    uint32_t shift = 0;
    for (;;) {
      char c = 0;
      input->get(c);
      field_size |= static_cast<uint32_t>(c & 0x7f) << shift;
      shift += 7;
      bytes_processed++;
      if (!(c & 0x80))
        break;
    }

    // ... and the actual TracePacket itself.
    std::unique_ptr<char[]> buf(new char[field_size]);
    input->read(buf.get(), static_cast<std::streamsize>(field_size));
    bytes_processed += field_size;

    f(std::move(buf), field_size);
  }
}

void ForEachPacketInTrace(
    std::istream* input,
    const std::function<void(const protos::TracePacket&)>& f) {
  ForEachPacketBlobInTrace(
      input, [f](std::unique_ptr<char[]> buf, size_t size) {
        protos::TracePacket packet;
        auto res = packet.ParseFromArray(buf.get(), static_cast<int>(size));
        if (!res) {
          PERFETTO_ELOG("Skipping invalid packet");
          return;
        }
        f(packet);
      });
  fprintf(stderr, "\n");
}

std::vector<std::string> GetPerfettoBinaryPath() {
  std::vector<std::string> roots;
  const char* root = getenv("PERFETTO_BINARY_PATH");
  if (root != nullptr) {
    for (base::StringSplitter sp(std::string(root), ':'); sp.Next();)
      roots.emplace_back(sp.cur_token(), sp.cur_token_size());
  }
  return roots;
}

bool ReadTrace(trace_processor::TraceProcessor* tp, std::istream* input) {
  // 1MB chunk size seems the best tradeoff on a MacBook Pro 2013 - i7 2.8 GHz.
  constexpr size_t kChunkSize = 1024 * 1024;

// Printing the status update on stderr can be a perf bottleneck. On WASM print
// status updates more frequently because it can be slower to parse each chunk.
#if PERFETTO_BUILDFLAG(PERFETTO_OS_WASM)
  constexpr int kStderrRate = 1;
#else
  constexpr int kStderrRate = 128;
#endif
  uint64_t file_size = 0;

  for (int i = 0;; i++) {
    if (i % kStderrRate == 0) {
      fprintf(stderr, "Loading trace %.2f MB%c", file_size / 1.0e6,
              kProgressChar);
      fflush(stderr);
    }

    std::unique_ptr<uint8_t[]> buf(new uint8_t[kChunkSize]);
    input->read(reinterpret_cast<char*>(buf.get()), kChunkSize);
    if (input->bad()) {
      PERFETTO_ELOG("Failed when reading trace");
      return false;
    }

    auto rsize = input->gcount();
    if (rsize <= 0)
      break;
    file_size += static_cast<uint64_t>(rsize);
    tp->Parse(std::move(buf), static_cast<size_t>(rsize));
  }

  fprintf(stderr, "Loaded trace%c", kProgressChar);
  fflush(stderr);
  return true;
}

void SymbolizeDatabase(
    trace_processor::TraceProcessor* tp,
    Symbolizer* symbolizer,
    std::function<void(perfetto::protos::TracePacket)> callback) {
  PERFETTO_CHECK(symbolizer);
  auto unsymbolized = GetUnsymbolizedFrames(tp);
  for (auto it = unsymbolized.cbegin(); it != unsymbolized.cend(); ++it) {
    const auto& name_and_buildid = it->first;
    const std::vector<uint64_t>& rel_pcs = it->second;
    auto res = symbolizer->Symbolize(name_and_buildid.first,
                                     name_and_buildid.second, rel_pcs);
    if (res.empty())
      continue;

    perfetto::protos::TracePacket packet;
    perfetto::protos::ModuleSymbols* module_symbols =
        packet.mutable_module_symbols();
    module_symbols->set_path(name_and_buildid.first);
    module_symbols->set_build_id(name_and_buildid.second);
    PERFETTO_DCHECK(res.size() == rel_pcs.size());
    for (size_t i = 0; i < res.size(); ++i) {
      auto* address_symbols = module_symbols->add_address_symbols();
      address_symbols->set_address(rel_pcs[i]);
      for (const SymbolizedFrame& frame : res[i]) {
        auto* line = address_symbols->add_lines();
        line->set_function_name(frame.function_name);
        line->set_source_file_name(frame.file_name);
        line->set_line_number(frame.line);
      }
    }
    callback(std::move(packet));
  }
}

TraceWriter::TraceWriter(std::ostream* output) : output_(output) {}

TraceWriter::~TraceWriter() = default;

void TraceWriter::Write(std::string s) {
  Write(s.data(), s.size());
}

void TraceWriter::Write(const char* data, size_t sz) {
  output_->write(data, static_cast<std::streamsize>(sz));
}

DeflateTraceWriter::DeflateTraceWriter(std::ostream* output)
    : TraceWriter(output),
      buf_(base::PagedMemory::Allocate(kCompressionBufferSize)),
      start_(static_cast<uint8_t*>(buf_.Get())),
      end_(start_ + buf_.size()) {
  CheckEq(deflateInit(&stream_, 9), Z_OK);
  stream_.next_out = start_;
  stream_.avail_out = static_cast<unsigned int>(end_ - start_);
}

DeflateTraceWriter::~DeflateTraceWriter() {
  while (deflate(&stream_, Z_FINISH) != Z_STREAM_END) {
    Flush();
  }
  CheckEq(deflateEnd(&stream_), Z_OK);
}

void DeflateTraceWriter::Write(const char* data, size_t sz) {
  stream_.next_in = reinterpret_cast<uint8_t*>(const_cast<char*>(data));
  stream_.avail_in = static_cast<unsigned int>(sz);
  while (stream_.avail_in > 0) {
    CheckEq(deflate(&stream_, Z_NO_FLUSH), Z_OK);
    if (stream_.avail_out == 0) {
      Flush();
    }
  }
}

void DeflateTraceWriter::Flush() {
  TraceWriter::Write(reinterpret_cast<char*>(start_),
                     static_cast<size_t>(stream_.next_out - start_));
  stream_.next_out = start_;
  stream_.avail_out = static_cast<unsigned int>(end_ - start_);
}

void DeflateTraceWriter::CheckEq(int actual_code, int expected_code) {
  if (actual_code == expected_code)
    return;
  PERFETTO_FATAL("Expected %d got %d: %s", actual_code, expected_code,
                 stream_.msg);
}

}  // namespace trace_to_text
}  // namespace perfetto