dump_cache.cc revision 5821806d5e7f356e8fa4b058a389a808ea183019 
1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5// This command-line program dumps the contents of a set of cache files, either
6// to stdout or to another set of cache files.
7
8#include <stdio.h>
9#include <string>
10
11#include "base/at_exit.h"
12#include "base/command_line.h"
13#include "base/process_util.h"
14#include "base/string_util.h"
15#include "base/stringprintf.h"
16#include "base/win/scoped_handle.h"
17#include "net/disk_cache/disk_format.h"
18
19enum Errors {
20  GENERIC = -1,
21  ALL_GOOD = 0,
22  INVALID_ARGUMENT = 1,
23  FILE_ACCESS_ERROR,
24  UNKNOWN_VERSION,
25  TOOL_NOT_FOUND,
26};
27
28int GetMajorVersion(const FilePath& input_path);
29int DumpContents(const FilePath& input_path);
30int DumpHeaders(const FilePath& input_path);
31int RunSlave(const FilePath& input_path, const std::wstring& pipe_number);
32int CopyCache(const FilePath& output_path, HANDLE pipe, bool copy_to_text);
33HANDLE CreateServer(std::wstring* pipe_number);
34
35const char kUpgradeHelp[] =
36    "\nIn order to use the upgrade function, a version of this tool that\n"
37    "understands the file format of the files to upgrade is needed. For\n"
38    "instance, to upgrade files saved with file format 3.4 to version 5.2,\n"
39    "a version of this program that was compiled with version 3.4 has to be\n"
40    "located beside this executable, and named dump_cache_3.exe, and this\n"
41    "executable should be compiled with version 5.2 being the current one.";
42
43// Folders to read and write cache files.
44const char kInputPath[] = "input";
45const char kOutputPath[] = "output";
46
47// Dumps the file headers to stdout.
48const char kDumpHeaders[] = "dump-headers";
49
50// Dumps all entries to stdout.
51const char kDumpContents[] = "dump-contents";
52
53// Convert the cache to files.
54const char kDumpToFiles[] = "dump-to-files";
55
56// Upgrade an old version to the current one.
57const char kUpgrade[] = "upgrade";
58
59// Internal use:
60const char kSlave[] = "slave";
61const char kPipe[] = "pipe";
62
63int Help() {
64  printf("warning: input files are modified by this tool\n");
65  printf("dump_cache --input=path1 [--output=path2]\n");
66  printf("--dump-headers: display file headers\n");
67  printf("--dump-contents: display all entries\n");
68  printf("--upgrade: copy contents to the output path\n");
69  printf("--dump-to-files: write the contents of the cache to files\n");
70  return INVALID_ARGUMENT;
71}
72
73// Starts a new process, to generate the files.
74int LaunchSlave(CommandLine command_line,
75                const std::wstring& pipe_number,
76                int version) {
77  bool do_upgrade = command_line.HasSwitch(kUpgrade);
78  bool do_convert_to_text = command_line.HasSwitch(kDumpToFiles);
79
80  if (do_upgrade) {
81    FilePath program(base::StringPrintf(L"%ls%d", L"dump_cache", version));
82    command_line.SetProgram(program);
83  }
84
85  if (do_upgrade || do_convert_to_text)
86    command_line.AppendSwitch(kSlave);
87
88  command_line.AppendSwitchNative(kPipe, pipe_number);
89  if (!base::LaunchProcess(command_line, base::LaunchOptions(), NULL)) {
90    printf("Unable to launch the needed version of this tool: %ls\n",
91           command_line.GetProgram().value().c_str());
92    printf(kUpgradeHelp);
93    return TOOL_NOT_FOUND;
94  }
95  return ALL_GOOD;
96}
97
98// -----------------------------------------------------------------------
99
100int main(int argc, const char* argv[]) {
101  // Setup an AtExitManager so Singleton objects will be destroyed.
102  base::AtExitManager at_exit_manager;
103
104  CommandLine::Init(argc, argv);
105
106  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
107  FilePath input_path = command_line.GetSwitchValuePath(kInputPath);
108  if (input_path.empty())
109    return Help();
110
111  bool upgrade = false;
112  bool slave_required = false;
113  bool copy_to_text = false;
114  FilePath output_path = command_line.GetSwitchValuePath(kOutputPath);
115
116  if (command_line.HasSwitch(kUpgrade))
117    upgrade = true;
118  if (command_line.HasSwitch(kDumpToFiles))
119    copy_to_text = true;
120
121  if (upgrade || copy_to_text) {
122    if (output_path.empty())
123      return Help();
124    slave_required = true;
125  }
126
127  int version = GetMajorVersion(input_path);
128  if (!version)
129    return FILE_ACCESS_ERROR;
130
131  if (version != disk_cache::kCurrentVersion >> 16) {
132    if (command_line.HasSwitch(kSlave)) {
133      printf("Unknown version\n");
134      return UNKNOWN_VERSION;
135    }
136    slave_required = true;
137  }
138
139  std::wstring pipe_number = command_line.GetSwitchValueNative(kPipe);
140  if (command_line.HasSwitch(kSlave) && slave_required)
141    return RunSlave(input_path, pipe_number);
142
143  base::win::ScopedHandle server;
144  if (slave_required) {
145    server.Set(CreateServer(&pipe_number));
146    if (!server.IsValid()) {
147      printf("Unable to create the server pipe\n");
148      return -1;
149    }
150
151    int ret = LaunchSlave(command_line, pipe_number, version);
152    if (ret)
153      return ret;
154  }
155
156  if (upgrade || copy_to_text)
157    return CopyCache(output_path, server, copy_to_text);
158
159  if (slave_required) {
160    // Wait until the slave starts dumping data before we quit. Lazy "fix" for a
161    // console quirk.
162    Sleep(500);
163    return ALL_GOOD;
164  }
165
166  if (command_line.HasSwitch(kDumpContents))
167    return DumpContents(input_path);
168  if (command_line.HasSwitch(kDumpHeaders))
169    return DumpHeaders(input_path);
170  return Help();
171}
172