src/startup-data-util.cc

// Copyright 2015 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/startup-data-util.h"

#include <stdlib.h>
#include <string.h>

#include "src/base/logging.h"


namespace v8 {

#ifdef V8_USE_EXTERNAL_STARTUP_DATA

StartupDataHandler::StartupDataHandler(const char* exec_path,
                                       const char* natives_blob,
                                       const char* snapshot_blob) {
  // If we have (at least one) explicitly given blob, use those.
  // If not, use the default blob locations next to the d8 binary.
  if (natives_blob || snapshot_blob) {
    LoadFromFiles(natives_blob, snapshot_blob);
  } else {
    char* natives;
    char* snapshot;
    LoadFromFiles(RelativePath(&natives, exec_path, "natives_blob.bin"),
                  RelativePath(&snapshot, exec_path, "snapshot_blob.bin"));

    free(natives);
    free(snapshot);
  }
}


StartupDataHandler::~StartupDataHandler() {
  delete[] natives_.data;
  delete[] snapshot_.data;
}


char* StartupDataHandler::RelativePath(char** buffer, const char* exec_path,
                                       const char* name) {
  DCHECK(exec_path);
  const char* last_slash = strrchr(exec_path, '/');
  if (last_slash) {
    int after_slash = last_slash - exec_path + 1;
    int name_length = static_cast<int>(strlen(name));
    *buffer = reinterpret_cast<char*>(calloc(after_slash + name_length + 1, 1));
    strncpy(*buffer, exec_path, after_slash);
    strncat(*buffer, name, name_length);
  } else {
    *buffer = strdup(name);
  }
  return *buffer;
}


void StartupDataHandler::LoadFromFiles(const char* natives_blob,
                                       const char* snapshot_blob) {
  Load(natives_blob, &natives_, v8::V8::SetNativesDataBlob);
  Load(snapshot_blob, &snapshot_, v8::V8::SetSnapshotDataBlob);
}


void StartupDataHandler::Load(const char* blob_file,
                              v8::StartupData* startup_data,
                              void (*setter_fn)(v8::StartupData*)) {
  startup_data->data = NULL;
  startup_data->raw_size = 0;

  if (!blob_file) return;

  FILE* file = fopen(blob_file, "rb");
  if (!file) return;

  fseek(file, 0, SEEK_END);
  startup_data->raw_size = ftell(file);
  rewind(file);

  startup_data->data = new char[startup_data->raw_size];
  int read_size = static_cast<int>(fread(const_cast<char*>(startup_data->data),
                                         1, startup_data->raw_size, file));
  fclose(file);

  if (startup_data->raw_size == read_size) (*setter_fn)(startup_data);
}

#endif  // V8_USE_EXTERNAL_STARTUP_DATA

}  // namespace v8