net/tools/dump_cache/dump_files.cc

   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 // Performs basic inspection of the disk cache files with minimal disruption
   6 // to the actual files (they still may change if an error is detected on the
   7 // files).
   8
   9 #include "net/tools/dump_cache/dump_files.h"
  10
  11 #include <stdio.h>
  12
  13 #include <set>
  14 #include <string>
  15
  16 #include "base/files/file.h"
  17 #include "base/files/file_enumerator.h"
  18 #include "base/files/file_util.h"
  19 #include "base/format_macros.h"
  20 #include "base/message_loop/message_loop.h"
  21 #include "net/disk_cache/blockfile/block_files.h"
  22 #include "net/disk_cache/blockfile/disk_format.h"
  23 #include "net/disk_cache/blockfile/mapped_file.h"
  24 #include "net/disk_cache/blockfile/stats.h"
  25 #include "net/disk_cache/blockfile/storage_block-inl.h"
  26 #include "net/disk_cache/blockfile/storage_block.h"
  27
  28 namespace {
  29
  30 const base::FilePath::CharType kIndexName[] = FILE_PATH_LITERAL("index");
  31
  32 // Reads the |header_size| bytes from the beginning of file |name|.
  33 bool ReadHeader(const base::FilePath& name, char* header, int header_size) {
  34   base::File file(name, base::File::FLAG_OPEN | base::File::FLAG_READ);
  35   if (!file.IsValid()) {
  36     printf("Unable to open file %s\n", name.MaybeAsASCII().c_str());
  37     return false;
  38   }
  39
  40   int read = file.Read(0, header, header_size);
  41   if (read != header_size) {
  42     printf("Unable to read file %s\n", name.MaybeAsASCII().c_str());
  43     return false;
  44   }
  45   return true;
  46 }
  47
  48 int GetMajorVersionFromFile(const base::FilePath& name) {
  49   disk_cache::IndexHeader header;
  50   if (!ReadHeader(name, reinterpret_cast<char*>(&header), sizeof(header)))
  51     return 0;
  52
  53   return header.version >> 16;
  54 }
  55
  56 // Dumps the contents of the Stats record.
  57 void DumpStats(const base::FilePath& path, disk_cache::CacheAddr addr) {
  58   // We need a message loop, although we really don't run any task.
  59   base::MessageLoopForIO loop;
  60
  61   disk_cache::BlockFiles block_files(path);
  62   if (!block_files.Init(false)) {
  63     printf("Unable to init block files\n");
  64     return;
  65   }
  66
  67   disk_cache::Addr address(addr);
  68   disk_cache::MappedFile* file = block_files.GetFile(address);
  69   if (!file)
  70     return;
  71
  72   size_t length = (2 + disk_cache::Stats::kDataSizesLength) * sizeof(int32) +
  73                   disk_cache::Stats::MAX_COUNTER * sizeof(int64);
  74
  75   size_t offset = address.start_block() * address.BlockSize() +
  76                   disk_cache::kBlockHeaderSize;
  77
  78   scoped_ptr<int32[]> buffer(new int32[length]);
  79   if (!file->Read(buffer.get(), length, offset))
  80     return;
  81
  82   printf("Stats:\nSignatrure: 0x%x\n", buffer[0]);
  83   printf("Total size: %d\n", buffer[1]);
  84   for (int i = 0; i < disk_cache::Stats::kDataSizesLength; i++)
  85     printf("Size(%d): %d\n", i, buffer[i + 2]);
  86
  87   int64* counters = reinterpret_cast<int64*>(
  88                         buffer.get() + 2 + disk_cache::Stats::kDataSizesLength);
  89   for (int i = 0; i < disk_cache::Stats::MAX_COUNTER; i++)
  90     printf("Count(%d): %" PRId64 "\n", i, *counters++);
  91   printf("-------------------------\n\n");
  92 }
  93
  94 // Dumps the contents of the Index-file header.
  95 void DumpIndexHeader(const base::FilePath& name,
  96                      disk_cache::CacheAddr* stats_addr) {
  97   disk_cache::IndexHeader header;
  98   if (!ReadHeader(name, reinterpret_cast<char*>(&header), sizeof(header)))
  99     return;
 100
 101   printf("Index file:\n");
 102   printf("magic: %x\n", header.magic);
 103   printf("version: %d.%d\n", header.version >> 16, header.version & 0xffff);
 104   printf("entries: %d\n", header.num_entries);
 105   printf("total bytes: %d\n", header.num_bytes);
 106   printf("last file number: %d\n", header.last_file);
 107   printf("current id: %d\n", header.this_id);
 108   printf("table length: %d\n", header.table_len);
 109   printf("last crash: %d\n", header.crash);
 110   printf("experiment: %d\n", header.experiment);
 111   printf("stats: %x\n", header.stats);
 112   for (int i = 0; i < 5; i++) {
 113     printf("head %d: 0x%x\n", i, header.lru.heads[i]);
 114     printf("tail %d: 0x%x\n", i, header.lru.tails[i]);
 115     printf("size %d: 0x%x\n", i, header.lru.sizes[i]);
 116   }
 117   printf("transaction: 0x%x\n", header.lru.transaction);
 118   printf("operation: %d\n", header.lru.operation);
 119   printf("operation list: %d\n", header.lru.operation_list);
 120   printf("-------------------------\n\n");
 121
 122   *stats_addr = header.stats;
 123 }
 124
 125 // Dumps the contents of a block-file header.
 126 void DumpBlockHeader(const base::FilePath& name) {
 127   disk_cache::BlockFileHeader header;
 128   if (!ReadHeader(name, reinterpret_cast<char*>(&header), sizeof(header)))
 129     return;
 130
 131   printf("Block file: %s\n", name.BaseName().MaybeAsASCII().c_str());
 132   printf("magic: %x\n", header.magic);
 133   printf("version: %d.%d\n", header.version >> 16, header.version & 0xffff);
 134   printf("file id: %d\n", header.this_file);
 135   printf("next file id: %d\n", header.next_file);
 136   printf("entry size: %d\n", header.entry_size);
 137   printf("current entries: %d\n", header.num_entries);
 138   printf("max entries: %d\n", header.max_entries);
 139   printf("updating: %d\n", header.updating);
 140   printf("empty sz 1: %d\n", header.empty[0]);
 141   printf("empty sz 2: %d\n", header.empty[1]);
 142   printf("empty sz 3: %d\n", header.empty[2]);
 143   printf("empty sz 4: %d\n", header.empty[3]);
 144   printf("user 0: 0x%x\n", header.user[0]);
 145   printf("user 1: 0x%x\n", header.user[1]);
 146   printf("user 2: 0x%x\n", header.user[2]);
 147   printf("user 3: 0x%x\n", header.user[3]);
 148   printf("-------------------------\n\n");
 149 }
 150
 151 // Simple class that interacts with the set of cache files.
 152 class CacheDumper {
 153  public:
 154   explicit CacheDumper(const base::FilePath& path)
 155       : path_(path),
 156         block_files_(path),
 157         index_(NULL),
 158         current_hash_(0),
 159         next_addr_(0) {
 160   }
 161
 162   bool Init();
 163
 164   // Reads an entry from disk. Return false when all entries have been already
 165   // returned.
 166   bool GetEntry(disk_cache::EntryStore* entry);
 167
 168   // Loads a specific block from the block files.
 169   bool LoadEntry(disk_cache::CacheAddr addr, disk_cache::EntryStore* entry);
 170   bool LoadRankings(disk_cache::CacheAddr addr,
 171                     disk_cache::RankingsNode* rankings);
 172
 173  private:
 174   base::FilePath path_;
 175   disk_cache::BlockFiles block_files_;
 176   scoped_refptr<disk_cache::MappedFile> index_file_;
 177   disk_cache::Index* index_;
 178   int current_hash_;
 179   disk_cache::CacheAddr next_addr_;
 180   std::set<disk_cache::CacheAddr> dumped_entries_;
 181   DISALLOW_COPY_AND_ASSIGN(CacheDumper);
 182 };
 183
 184 bool CacheDumper::Init() {
 185   if (!block_files_.Init(false)) {
 186     printf("Unable to init block files\n");
 187     return false;
 188   }
 189
 190   base::FilePath index_name(path_.Append(kIndexName));
 191   index_file_ = new disk_cache::MappedFile;
 192   index_ = reinterpret_cast<disk_cache::Index*>(
 193       index_file_->Init(index_name, 0));
 194   if (!index_) {
 195     printf("Unable to map index\n");
 196     return false;
 197   }
 198
 199   return true;
 200 }
 201
 202 bool CacheDumper::GetEntry(disk_cache::EntryStore* entry) {
 203   if (dumped_entries_.find(next_addr_) != dumped_entries_.end()) {
 204     printf("Loop detected\n");
 205     next_addr_ = 0;
 206     current_hash_++;
 207   }
 208
 209   if (next_addr_) {
 210     if (LoadEntry(next_addr_, entry))
 211       return true;
 212
 213     printf("Unable to load entry at address 0x%x\n", next_addr_);
 214     next_addr_ = 0;
 215     current_hash_++;
 216   }
 217
 218   for (int i = current_hash_; i < index_->header.table_len; i++) {
 219     // Yes, we'll crash if the table is shorter than expected, but only after
 220     // dumping every entry that we can find.
 221     if (index_->table[i]) {
 222       current_hash_ = i;
 223       if (LoadEntry(index_->table[i], entry))
 224         return true;
 225
 226       printf("Unable to load entry at address 0x%x\n", index_->table[i]);
 227     }
 228   }
 229   return false;
 230 }
 231
 232 bool CacheDumper::LoadEntry(disk_cache::CacheAddr addr,
 233                             disk_cache::EntryStore* entry) {
 234   disk_cache::Addr address(addr);
 235   disk_cache::MappedFile* file = block_files_.GetFile(address);
 236   if (!file)
 237     return false;
 238
 239   disk_cache::StorageBlock<disk_cache::EntryStore> entry_block(file, address);
 240   if (!entry_block.Load())
 241     return false;
 242
 243   memcpy(entry, entry_block.Data(), sizeof(*entry));
 244   printf("Entry at 0x%x\n", addr);
 245
 246   // Prepare for the next entry to load.
 247   next_addr_ = entry->next;
 248   if (next_addr_) {
 249     dumped_entries_.insert(addr);
 250   } else {
 251     current_hash_++;
 252     dumped_entries_.clear();
 253   }
 254   return true;
 255 }
 256
 257 bool CacheDumper::LoadRankings(disk_cache::CacheAddr addr,
 258                                disk_cache::RankingsNode* rankings) {
 259   disk_cache::Addr address(addr);
 260   disk_cache::MappedFile* file = block_files_.GetFile(address);
 261   if (!file)
 262     return false;
 263
 264   disk_cache::StorageBlock<disk_cache::RankingsNode> rank_block(file, address);
 265   if (!rank_block.Load())
 266     return false;
 267
 268   memcpy(rankings, rank_block.Data(), sizeof(*rankings));
 269   printf("Rankings at 0x%x\n", addr);
 270   return true;
 271 }
 272
 273 void DumpEntry(const disk_cache::EntryStore& entry) {
 274   std::string key;
 275   if (!entry.long_key) {
 276     key = entry.key;
 277     if (key.size() > 50)
 278       key.resize(50);
 279   }
 280
 281   printf("hash: 0x%x\n", entry.hash);
 282   printf("next entry: 0x%x\n", entry.next);
 283   printf("rankings: 0x%x\n", entry.rankings_node);
 284   printf("key length: %d\n", entry.key_len);
 285   printf("key: \"%s\"\n", key.c_str());
 286   printf("key addr: 0x%x\n", entry.long_key);
 287   printf("reuse count: %d\n", entry.reuse_count);
 288   printf("refetch count: %d\n", entry.refetch_count);
 289   printf("state: %d\n", entry.state);
 290   for (int i = 0; i < 4; i++) {
 291     printf("data size %d: %d\n", i, entry.data_size[i]);
 292     printf("data addr %d: 0x%x\n", i, entry.data_addr[i]);
 293   }
 294   printf("----------\n\n");
 295 }
 296
 297 void DumpRankings(const disk_cache::RankingsNode& rankings) {
 298   printf("next: 0x%x\n", rankings.next);
 299   printf("prev: 0x%x\n", rankings.prev);
 300   printf("entry: 0x%x\n", rankings.contents);
 301   printf("dirty: %d\n", rankings.dirty);
 302   printf("hash: 0x%x\n", rankings.self_hash);
 303   printf("----------\n\n");
 304 }
 305
 306 }  // namespace.
 307
 308 // -----------------------------------------------------------------------
 309
 310 int GetMajorVersion(const base::FilePath& input_path) {
 311   base::FilePath index_name(input_path.Append(kIndexName));
 312
 313   int version = GetMajorVersionFromFile(index_name);
 314   if (!version)
 315     return 0;
 316
 317   base::FilePath data_name(input_path.Append(FILE_PATH_LITERAL("data_0")));
 318   if (version != GetMajorVersionFromFile(data_name))
 319     return 0;
 320
 321   data_name = input_path.Append(FILE_PATH_LITERAL("data_1"));
 322   if (version != GetMajorVersionFromFile(data_name))
 323     return 0;
 324
 325   data_name = input_path.Append(FILE_PATH_LITERAL("data_2"));
 326   if (version != GetMajorVersionFromFile(data_name))
 327     return 0;
 328
 329   data_name = input_path.Append(FILE_PATH_LITERAL("data_3"));
 330   if (version != GetMajorVersionFromFile(data_name))
 331     return 0;
 332
 333   return version;
 334 }
 335
 336 // Dumps the headers of all files.
 337 int DumpHeaders(const base::FilePath& input_path) {
 338   base::FilePath index_name(input_path.Append(kIndexName));
 339   disk_cache::CacheAddr stats_addr = 0;
 340   DumpIndexHeader(index_name, &stats_addr);
 341
 342   base::FileEnumerator iter(input_path, false,
 343                             base::FileEnumerator::FILES,
 344                             FILE_PATH_LITERAL("data_*"));
 345   for (base::FilePath file = iter.Next(); !file.empty(); file = iter.Next())
 346     DumpBlockHeader(file);
 347
 348   DumpStats(input_path, stats_addr);
 349   return 0;
 350 }
 351
 352 // Dumps all entries from the cache.
 353 int DumpContents(const base::FilePath& input_path) {
 354   DumpHeaders(input_path);
 355
 356   // We need a message loop, although we really don't run any task.
 357   base::MessageLoopForIO loop;
 358   CacheDumper dumper(input_path);
 359   if (!dumper.Init())
 360     return -1;
 361
 362   disk_cache::EntryStore entry;
 363   while (dumper.GetEntry(&entry)) {
 364     DumpEntry(entry);
 365     disk_cache::RankingsNode rankings;
 366     if (dumper.LoadRankings(entry.rankings_node, &rankings))
 367       DumpRankings(rankings);
 368   }
 369
 370   printf("Done.\n");
 371
 372   return 0;
 373 }