summaryrefslogtreecommitdiffstats
path: root/src/build_log.cc
blob: b6f98745788c564787b7f0e8045763a457a0464a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
// Copyright 2011 Google Inc. All Rights Reserved.
//
// 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 "build_log.h"

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

#ifndef _WIN32
#define __STDC_FORMAT_MACROS
#include <inttypes.h>
#include <unistd.h>
#endif

#include "build.h"
#include "graph.h"
#include "metrics.h"
#include "util.h"

// Implementation details:
// Each run's log appends to the log file.
// To load, we run through all log entries in series, throwing away
// older runs.
// Once the number of redundant entries exceeds a threshold, we write
// out a new file and replace the existing one with it.

namespace {

const char kFileSignature[] = "# ninja log v%d\n";
const int kOldestSupportedVersion = 4;
const int kCurrentVersion = 5;

// 64bit MurmurHash2, by Austin Appleby
#if defined(_MSC_VER)
#define BIG_CONSTANT(x) (x)
#else   // defined(_MSC_VER)
#define BIG_CONSTANT(x) (x##LLU)
#endif // !defined(_MSC_VER)
inline
uint64_t MurmurHash64A(const void* key, size_t len) {
  static const uint64_t seed = 0xDECAFBADDECAFBADull;
  const uint64_t m = BIG_CONSTANT(0xc6a4a7935bd1e995);
  const int r = 47;
  uint64_t h = seed ^ (len * m);
  const unsigned char* data = (const unsigned char*)key;
  while (len >= 8) {
    uint64_t k;
    memcpy(&k, data, sizeof k);
    k *= m;
    k ^= k >> r;
    k *= m;
    h ^= k;
    h *= m;
    data += 8;
    len -= 8;
  }
  switch (len & 7)
  {
  case 7: h ^= uint64_t(data[6]) << 48;
  case 6: h ^= uint64_t(data[5]) << 40;
  case 5: h ^= uint64_t(data[4]) << 32;
  case 4: h ^= uint64_t(data[3]) << 24;
  case 3: h ^= uint64_t(data[2]) << 16;
  case 2: h ^= uint64_t(data[1]) << 8;
  case 1: h ^= uint64_t(data[0]);
          h *= m;
  };
  h ^= h >> r;
  h *= m;
  h ^= h >> r;
  return h;
}
#undef BIG_CONSTANT


}  // namespace

// static
uint64_t BuildLog::LogEntry::HashCommand(StringPiece command) {
  return MurmurHash64A(command.str_, command.len_);
}

BuildLog::LogEntry::LogEntry(const string& output)
  : output(output) {}

BuildLog::LogEntry::LogEntry(const string& output, uint64_t command_hash,
  int start_time, int end_time, TimeStamp restat_mtime)
  : output(output), command_hash(command_hash),
    start_time(start_time), end_time(end_time), restat_mtime(restat_mtime)
{}

BuildLog::BuildLog()
  : log_file_(NULL), needs_recompaction_(false), quiet_(false) {}

BuildLog::~BuildLog() {
  Close();
}

bool BuildLog::OpenForWrite(const string& path, const BuildLogUser& user,
                            string* err) {
  if (needs_recompaction_) {
    if (!Recompact(path, user, err))
      return false;
  }

  log_file_ = fopen(path.c_str(), "ab");
  if (!log_file_) {
    *err = strerror(errno);
    return false;
  }
  setvbuf(log_file_, NULL, _IOLBF, BUFSIZ);
  SetCloseOnExec(fileno(log_file_));

  // Opening a file in append mode doesn't set the file pointer to the file's
  // end on Windows. Do that explicitly.
  fseek(log_file_, 0, SEEK_END);

  if (ftell(log_file_) == 0) {
    if (fprintf(log_file_, kFileSignature, kCurrentVersion) < 0) {
      *err = strerror(errno);
      return false;
    }
  }

  return true;
}

bool BuildLog::RecordCommand(Edge* edge, int start_time, int end_time,
                             TimeStamp restat_mtime) {
  string command = edge->EvaluateCommand(true);
  uint64_t command_hash = LogEntry::HashCommand(command);
  for (vector<Node*>::iterator out = edge->outputs_.begin();
       out != edge->outputs_.end(); ++out) {
    const string& path = (*out)->path();
    Entries::iterator i = entries_.find(path);
    LogEntry* log_entry;
    if (i != entries_.end()) {
      log_entry = i->second;
    } else {
      log_entry = new LogEntry(path);
      entries_.insert(Entries::value_type(log_entry->output, log_entry));
    }
    log_entry->command_hash = command_hash;
    log_entry->start_time = start_time;
    log_entry->end_time = end_time;
    log_entry->restat_mtime = restat_mtime;

    if (log_file_) {
      if (!WriteEntry(log_file_, *log_entry))
        return false;
    }
  }
  return true;
}

void BuildLog::Close() {
  if (log_file_)
    fclose(log_file_);
  log_file_ = NULL;
}

struct LineReader {
  explicit LineReader(FILE* file)
    : file_(file), buf_end_(buf_), line_start_(buf_), line_end_(NULL) {
      memset(buf_, 0, sizeof(buf_));
  }

  // Reads a \n-terminated line from the file passed to the constructor.
  // On return, *line_start points to the beginning of the next line, and
  // *line_end points to the \n at the end of the line. If no newline is seen
  // in a fixed buffer size, *line_end is set to NULL. Returns false on EOF.
  bool ReadLine(char** line_start, char** line_end) {
    if (line_start_ >= buf_end_ || !line_end_) {
      // Buffer empty, refill.
      size_t size_read = fread(buf_, 1, sizeof(buf_), file_);
      if (!size_read)
        return false;
      line_start_ = buf_;
      buf_end_ = buf_ + size_read;
    } else {
      // Advance to next line in buffer.
      line_start_ = line_end_ + 1;
    }

    line_end_ = (char*)memchr(line_start_, '\n', buf_end_ - line_start_);
    if (!line_end_) {
      // No newline. Move rest of data to start of buffer, fill rest.
      size_t already_consumed = line_start_ - buf_;
      size_t size_rest = (buf_end_ - buf_) - already_consumed;
      memmove(buf_, line_start_, size_rest);

      size_t read = fread(buf_ + size_rest, 1, sizeof(buf_) - size_rest, file_);
      buf_end_ = buf_ + size_rest + read;
      line_start_ = buf_;
      line_end_ = (char*)memchr(line_start_, '\n', buf_end_ - line_start_);
    }

    *line_start = line_start_;
    *line_end = line_end_;
    return true;
  }

 private:
  FILE* file_;
  char buf_[256 << 10];
  char* buf_end_;  // Points one past the last valid byte in |buf_|.

  char* line_start_;
  // Points at the next \n in buf_ after line_start, or NULL.
  char* line_end_;
};

bool BuildLog::Load(const string& path, string* err) {
  METRIC_RECORD(".ninja_log load");
  FILE* file = fopen(path.c_str(), "r");
  if (!file) {
    if (errno == ENOENT)
      return true;
    *err = strerror(errno);
    return false;
  }

  int log_version = 0;
  int unique_entry_count = 0;
  int total_entry_count = 0;

  LineReader reader(file);
  char* line_start = 0;
  char* line_end = 0;
  while (reader.ReadLine(&line_start, &line_end)) {
    if (!log_version) {
      sscanf(line_start, kFileSignature, &log_version);

      if (log_version < kOldestSupportedVersion) {
        *err = ("build log version invalid, perhaps due to being too old; "
                "starting over");
        fclose(file);
        unlink(path.c_str());
        // Don't report this as a failure.  An empty build log will cause
        // us to rebuild the outputs anyway.
        return true;
      }
    }

    // If no newline was found in this chunk, read the next.
    if (!line_end)
      continue;

    const char kFieldSeparator = '\t';

    char* start = line_start;
    char* end = (char*)memchr(start, kFieldSeparator, line_end - start);
    if (!end)
      continue;
    *end = 0;

    int start_time = 0, end_time = 0;
    TimeStamp restat_mtime = 0;

    start_time = atoi(start);
    start = end + 1;

    end = (char*)memchr(start, kFieldSeparator, line_end - start);
    if (!end)
      continue;
    *end = 0;
    end_time = atoi(start);
    start = end + 1;

    end = (char*)memchr(start, kFieldSeparator, line_end - start);
    if (!end)
      continue;
    *end = 0;
    restat_mtime = atol(start);
    start = end + 1;

    end = (char*)memchr(start, kFieldSeparator, line_end - start);
    if (!end)
      continue;
    string output = string(start, end - start);

    start = end + 1;
    end = line_end;

    LogEntry* entry;
    Entries::iterator i = entries_.find(output);
    if (i != entries_.end()) {
      entry = i->second;
    } else {
      entry = new LogEntry(output);
      entries_.insert(Entries::value_type(entry->output, entry));
      ++unique_entry_count;
    }
    ++total_entry_count;

    entry->start_time = start_time;
    entry->end_time = end_time;
    entry->restat_mtime = restat_mtime;
    if (log_version >= 5) {
      char c = *end; *end = '\0';
      entry->command_hash = (uint64_t)strtoull(start, NULL, 16);
      *end = c;
    } else {
      entry->command_hash = LogEntry::HashCommand(StringPiece(start,
                                                              end - start));
    }
  }
  fclose(file);

  if (!line_start) {
    return true; // file was empty
  }

  // Decide whether it's time to rebuild the log:
  // - if we're upgrading versions
  // - if it's getting large
  int kMinCompactionEntryCount = 100;
  int kCompactionRatio = 3;
  if (log_version < kCurrentVersion) {
    needs_recompaction_ = true;
  } else if (total_entry_count > kMinCompactionEntryCount &&
             total_entry_count > unique_entry_count * kCompactionRatio) {
    needs_recompaction_ = true;
  }

  return true;
}

BuildLog::LogEntry* BuildLog::LookupByOutput(const string& path) {
  Entries::iterator i = entries_.find(path);
  if (i != entries_.end())
    return i->second;
  return NULL;
}

bool BuildLog::WriteEntry(FILE* f, const LogEntry& entry) {
  return fprintf(f, "%d\t%d\t%d\t%s\t%" PRIx64 "\n",
          entry.start_time, entry.end_time, entry.restat_mtime,
          entry.output.c_str(), entry.command_hash) > 0;
}

bool BuildLog::Recompact(const string& path, const BuildLogUser& user,
                         string* err) {
  METRIC_RECORD(".ninja_log recompact");
  if (!quiet_)
    printf("Recompacting log...\n");

  Close();
  string temp_path = path + ".recompact";
  FILE* f = fopen(temp_path.c_str(), "wb");
  if (!f) {
    *err = strerror(errno);
    return false;
  }

  if (fprintf(f, kFileSignature, kCurrentVersion) < 0) {
    *err = strerror(errno);
    fclose(f);
    return false;
  }

  vector<StringPiece> dead_outputs;
  for (Entries::iterator i = entries_.begin(); i != entries_.end(); ++i) {
    if (user.IsPathDead(i->first)) {
      dead_outputs.push_back(i->first);
      continue;
    }

    if (!WriteEntry(f, *i->second)) {
      *err = strerror(errno);
      fclose(f);
      return false;
    }
  }

  for (size_t i = 0; i < dead_outputs.size(); ++i)
    entries_.erase(dead_outputs[i]);

  fclose(f);
  if (unlink(path.c_str()) < 0) {
    *err = strerror(errno);
    return false;
  }

  if (rename(temp_path.c_str(), path.c_str()) < 0) {
    *err = strerror(errno);
    return false;
  }

  return true;
}