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
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
|
// Copyright 2012 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 "deps_log.h"
#include <assert.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#ifndef _WIN32
#include <unistd.h>
#elif defined(_MSC_VER) && (_MSC_VER < 1900)
typedef __int32 int32_t;
typedef unsigned __int32 uint32_t;
#endif
#include "graph.h"
#include "metrics.h"
#include "state.h"
#include "util.h"
using namespace std;
// The version is stored as 4 bytes after the signature and also serves as a
// byte order mark. Signature and version combined are 16 bytes long.
const char kFileSignature[] = "# ninjadeps\n";
const int kCurrentVersion = 4;
// Record size is currently limited to less than the full 32 bit, due to
// internal buffers having to have this size.
const unsigned kMaxRecordSize = (1 << 19) - 1;
DepsLog::~DepsLog() {
Close();
}
bool DepsLog::OpenForWrite(const string& path, string* err) {
if (needs_recompaction_) {
if (!Recompact(path, err))
return false;
}
assert(!file_);
file_path_ = path; // we don't actually open the file right now, but will do
// so on the first write attempt
return true;
}
bool DepsLog::RecordDeps(Node* node, TimeStamp mtime,
const vector<Node*>& nodes) {
return RecordDeps(node, mtime, nodes.size(),
nodes.empty() ? NULL : (Node**)&nodes.front());
}
bool DepsLog::RecordDeps(Node* node, TimeStamp mtime,
int node_count, Node** nodes) {
// Track whether there's any new data to be recorded.
bool made_change = false;
// Assign ids to all nodes that are missing one.
if (node->id() < 0) {
if (!RecordId(node))
return false;
made_change = true;
}
for (int i = 0; i < node_count; ++i) {
if (nodes[i]->id() < 0) {
if (!RecordId(nodes[i]))
return false;
made_change = true;
}
}
// See if the new data is different than the existing data, if any.
if (!made_change) {
Deps* deps = GetDeps(node);
if (!deps ||
deps->mtime != mtime ||
deps->node_count != node_count) {
made_change = true;
} else {
for (int i = 0; i < node_count; ++i) {
if (deps->nodes[i] != nodes[i]) {
made_change = true;
break;
}
}
}
}
// Don't write anything if there's no new info.
if (!made_change)
return true;
// Update on-disk representation.
unsigned size = 4 * (1 + 2 + node_count);
if (size > kMaxRecordSize) {
errno = ERANGE;
return false;
}
if (!OpenForWriteIfNeeded()) {
return false;
}
size |= 0x80000000; // Deps record: set high bit.
if (fwrite(&size, 4, 1, file_) < 1)
return false;
int id = node->id();
if (fwrite(&id, 4, 1, file_) < 1)
return false;
uint32_t mtime_part = static_cast<uint32_t>(mtime & 0xffffffff);
if (fwrite(&mtime_part, 4, 1, file_) < 1)
return false;
mtime_part = static_cast<uint32_t>((mtime >> 32) & 0xffffffff);
if (fwrite(&mtime_part, 4, 1, file_) < 1)
return false;
for (int i = 0; i < node_count; ++i) {
id = nodes[i]->id();
if (fwrite(&id, 4, 1, file_) < 1)
return false;
}
if (fflush(file_) != 0)
return false;
// Update in-memory representation.
Deps* deps = new Deps(mtime, node_count);
for (int i = 0; i < node_count; ++i)
deps->nodes[i] = nodes[i];
UpdateDeps(node->id(), deps);
return true;
}
void DepsLog::Close() {
OpenForWriteIfNeeded(); // create the file even if nothing has been recorded
if (file_)
fclose(file_);
file_ = NULL;
}
LoadStatus DepsLog::Load(const string& path, State* state, string* err) {
METRIC_RECORD(".ninja_deps load");
char buf[kMaxRecordSize + 1];
FILE* f = fopen(path.c_str(), "rb");
if (!f) {
if (errno == ENOENT)
return LOAD_NOT_FOUND;
*err = strerror(errno);
return LOAD_ERROR;
}
bool valid_header = true;
int version = 0;
if (!fgets(buf, sizeof(buf), f) || fread(&version, 4, 1, f) < 1)
valid_header = false;
// Note: For version differences, this should migrate to the new format.
// But the v1 format could sometimes (rarely) end up with invalid data, so
// don't migrate v1 to v3 to force a rebuild. (v2 only existed for a few days,
// and there was no release with it, so pretend that it never happened.)
if (!valid_header || strcmp(buf, kFileSignature) != 0 ||
version != kCurrentVersion) {
if (version == 1)
*err = "deps log version change; rebuilding";
else
*err = "bad deps log signature or version; starting over";
fclose(f);
unlink(path.c_str());
// Don't report this as a failure. An empty deps log will cause
// us to rebuild the outputs anyway.
return LOAD_SUCCESS;
}
long offset;
bool read_failed = false;
int unique_dep_record_count = 0;
int total_dep_record_count = 0;
for (;;) {
offset = ftell(f);
unsigned size;
if (fread(&size, 4, 1, f) < 1) {
if (!feof(f))
read_failed = true;
break;
}
bool is_deps = (size >> 31) != 0;
size = size & 0x7FFFFFFF;
if (size > kMaxRecordSize || fread(buf, size, 1, f) < 1) {
read_failed = true;
break;
}
if (is_deps) {
assert(size % 4 == 0);
int* deps_data = reinterpret_cast<int*>(buf);
int out_id = deps_data[0];
TimeStamp mtime;
mtime = (TimeStamp)(((uint64_t)(unsigned int)deps_data[2] << 32) |
(uint64_t)(unsigned int)deps_data[1]);
deps_data += 3;
int deps_count = (size / 4) - 3;
Deps* deps = new Deps(mtime, deps_count);
for (int i = 0; i < deps_count; ++i) {
assert(deps_data[i] < (int)nodes_.size());
assert(nodes_[deps_data[i]]);
deps->nodes[i] = nodes_[deps_data[i]];
}
total_dep_record_count++;
if (!UpdateDeps(out_id, deps))
++unique_dep_record_count;
} else {
int path_size = size - 4;
assert(path_size > 0); // CanonicalizePath() rejects empty paths.
// There can be up to 3 bytes of padding.
if (buf[path_size - 1] == '\0') --path_size;
if (buf[path_size - 1] == '\0') --path_size;
if (buf[path_size - 1] == '\0') --path_size;
StringPiece subpath(buf, path_size);
// It is not necessary to pass in a correct slash_bits here. It will
// either be a Node that's in the manifest (in which case it will already
// have a correct slash_bits that GetNode will look up), or it is an
// implicit dependency from a .d which does not affect the build command
// (and so need not have its slashes maintained).
Node* node = state->GetNode(subpath, 0);
// Check that the expected index matches the actual index. This can only
// happen if two ninja processes write to the same deps log concurrently.
// (This uses unary complement to make the checksum look less like a
// dependency record entry.)
unsigned checksum = *reinterpret_cast<unsigned*>(buf + size - 4);
int expected_id = ~checksum;
int id = nodes_.size();
if (id != expected_id) {
read_failed = true;
break;
}
assert(node->id() < 0);
node->set_id(id);
nodes_.push_back(node);
}
}
if (read_failed) {
// An error occurred while loading; try to recover by truncating the
// file to the last fully-read record.
if (ferror(f)) {
*err = strerror(ferror(f));
} else {
*err = "premature end of file";
}
fclose(f);
if (!Truncate(path, offset, err))
return LOAD_ERROR;
// The truncate succeeded; we'll just report the load error as a
// warning because the build can proceed.
*err += "; recovering";
return LOAD_SUCCESS;
}
fclose(f);
// Rebuild the log if there are too many dead records.
int kMinCompactionEntryCount = 1000;
int kCompactionRatio = 3;
if (total_dep_record_count > kMinCompactionEntryCount &&
total_dep_record_count > unique_dep_record_count * kCompactionRatio) {
needs_recompaction_ = true;
}
return LOAD_SUCCESS;
}
DepsLog::Deps* DepsLog::GetDeps(Node* node) {
// Abort if the node has no id (never referenced in the deps) or if
// there's no deps recorded for the node.
if (node->id() < 0 || node->id() >= (int)deps_.size())
return NULL;
return deps_[node->id()];
}
Node* DepsLog::GetFirstReverseDepsNode(Node* node) {
for (size_t id = 0; id < deps_.size(); ++id) {
Deps* deps = deps_[id];
if (!deps)
continue;
for (int i = 0; i < deps->node_count; ++i) {
if (deps->nodes[i] == node)
return nodes_[id];
}
}
return NULL;
}
bool DepsLog::Recompact(const string& path, string* err) {
METRIC_RECORD(".ninja_deps recompact");
Close();
string temp_path = path + ".recompact";
// OpenForWrite() opens for append. Make sure it's not appending to a
// left-over file from a previous recompaction attempt that crashed somehow.
unlink(temp_path.c_str());
DepsLog new_log;
if (!new_log.OpenForWrite(temp_path, err))
return false;
// Clear all known ids so that new ones can be reassigned. The new indices
// will refer to the ordering in new_log, not in the current log.
for (vector<Node*>::iterator i = nodes_.begin(); i != nodes_.end(); ++i)
(*i)->set_id(-1);
// Write out all deps again.
for (int old_id = 0; old_id < (int)deps_.size(); ++old_id) {
Deps* deps = deps_[old_id];
if (!deps) continue; // If nodes_[old_id] is a leaf, it has no deps.
if (!IsDepsEntryLiveFor(nodes_[old_id]))
continue;
if (!new_log.RecordDeps(nodes_[old_id], deps->mtime,
deps->node_count, deps->nodes)) {
new_log.Close();
return false;
}
}
new_log.Close();
// All nodes now have ids that refer to new_log, so steal its data.
deps_.swap(new_log.deps_);
nodes_.swap(new_log.nodes_);
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;
}
bool DepsLog::IsDepsEntryLiveFor(Node* node) {
// Skip entries that don't have in-edges or whose edges don't have a
// "deps" attribute. They were in the deps log from previous builds, but
// the the files they were for were removed from the build and their deps
// entries are no longer needed.
// (Without the check for "deps", a chain of two or more nodes that each
// had deps wouldn't be collected in a single recompaction.)
return node->in_edge() && !node->in_edge()->GetBinding("deps").empty();
}
bool DepsLog::UpdateDeps(int out_id, Deps* deps) {
if (out_id >= (int)deps_.size())
deps_.resize(out_id + 1);
bool delete_old = deps_[out_id] != NULL;
if (delete_old)
delete deps_[out_id];
deps_[out_id] = deps;
return delete_old;
}
bool DepsLog::RecordId(Node* node) {
int path_size = node->path().size();
int padding = (4 - path_size % 4) % 4; // Pad path to 4 byte boundary.
unsigned size = path_size + padding + 4;
if (size > kMaxRecordSize) {
errno = ERANGE;
return false;
}
if (!OpenForWriteIfNeeded()) {
return false;
}
if (fwrite(&size, 4, 1, file_) < 1)
return false;
if (fwrite(node->path().data(), path_size, 1, file_) < 1) {
assert(!node->path().empty());
return false;
}
if (padding && fwrite("\0\0", padding, 1, file_) < 1)
return false;
int id = nodes_.size();
unsigned checksum = ~(unsigned)id;
if (fwrite(&checksum, 4, 1, file_) < 1)
return false;
if (fflush(file_) != 0)
return false;
node->set_id(id);
nodes_.push_back(node);
return true;
}
bool DepsLog::OpenForWriteIfNeeded() {
if (file_path_.empty()) {
return true;
}
file_ = fopen(file_path_.c_str(), "ab");
if (!file_) {
return false;
}
// Set the buffer size to this and flush the file buffer after every record
// to make sure records aren't written partially.
if (setvbuf(file_, NULL, _IOFBF, kMaxRecordSize + 1) != 0) {
return false;
}
SetCloseOnExec(fileno(file_));
// Opening a file in append mode doesn't set the file pointer to the file's
// end on Windows. Do that explicitly.
fseek(file_, 0, SEEK_END);
if (ftell(file_) == 0) {
if (fwrite(kFileSignature, sizeof(kFileSignature) - 1, 1, file_) < 1) {
return false;
}
if (fwrite(&kCurrentVersion, 4, 1, file_) < 1) {
return false;
}
}
if (fflush(file_) != 0) {
return false;
}
file_path_.clear();
return true;
}
|