1 // Copyright 2012 Google Inc. All Rights Reserved.
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
7 // http://www.apache.org/licenses/LICENSE-2.0
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
30 // The version is stored as 4 bytes after the signature and also serves as a
31 // byte order mark. Signature and version combined are 16 bytes long.
32 const char kFileSignature[] = "# ninjadeps\n";
33 const int kCurrentVersion = 1;
39 bool DepsLog::OpenForWrite(const string& path, string* err) {
40 file_ = fopen(path.c_str(), "ab");
42 *err = strerror(errno);
45 SetCloseOnExec(fileno(file_));
47 // Opening a file in append mode doesn't set the file pointer to the file's
48 // end on Windows. Do that explicitly.
49 fseek(file_, 0, SEEK_END);
51 if (ftell(file_) == 0) {
52 if (fwrite(kFileSignature, sizeof(kFileSignature) - 1, 1, file_) < 1) {
53 *err = strerror(errno);
56 if (fwrite(&kCurrentVersion, 4, 1, file_) < 1) {
57 *err = strerror(errno);
65 bool DepsLog::RecordDeps(Node* node, TimeStamp mtime,
66 const vector<Node*>& nodes) {
67 return RecordDeps(node, mtime, nodes.size(),
68 nodes.empty() ? NULL : (Node**)&nodes.front());
71 bool DepsLog::RecordDeps(Node* node, TimeStamp mtime,
72 int node_count, Node** nodes) {
73 // Track whether there's any new data to be recorded.
74 bool made_change = false;
76 // Assign ids to all nodes that are missing one.
81 for (int i = 0; i < node_count; ++i) {
82 if (nodes[i]->id() < 0) {
88 // See if the new data is different than the existing data, if any.
90 Deps* deps = GetDeps(node);
92 deps->mtime != mtime ||
93 deps->node_count != node_count) {
96 for (int i = 0; i < node_count; ++i) {
97 if (deps->nodes[i] != nodes[i]) {
105 // Don't write anything if there's no new info.
109 // Update on-disk representation.
110 uint16_t size = 4 * (1 + 1 + (uint16_t)node_count);
111 size |= 0x8000; // Deps record: set high bit.
112 fwrite(&size, 2, 1, file_);
114 fwrite(&id, 4, 1, file_);
115 int timestamp = mtime;
116 fwrite(×tamp, 4, 1, file_);
117 for (int i = 0; i < node_count; ++i) {
119 fwrite(&id, 4, 1, file_);
122 // Update in-memory representation.
123 Deps* deps = new Deps(mtime, node_count);
124 for (int i = 0; i < node_count; ++i)
125 deps->nodes[i] = nodes[i];
126 UpdateDeps(node->id(), deps);
131 void DepsLog::Close() {
137 bool DepsLog::Load(const string& path, State* state, string* err) {
138 METRIC_RECORD(".ninja_deps load");
140 FILE* f = fopen(path.c_str(), "rb");
144 *err = strerror(errno);
148 bool valid_header = true;
150 if (!fgets(buf, sizeof(buf), f) || fread(&version, 4, 1, f) < 1)
151 valid_header = false;
152 if (!valid_header || strcmp(buf, kFileSignature) != 0 ||
153 version != kCurrentVersion) {
154 *err = "bad deps log signature or version; starting over";
156 unlink(path.c_str());
157 // Don't report this as a failure. An empty deps log will cause
158 // us to rebuild the outputs anyway.
163 bool read_failed = false;
168 if (fread(&size, 2, 1, f) < 1) {
173 bool is_deps = (size >> 15) != 0;
174 size = size & 0x7FFF;
176 if (fread(buf, size, 1, f) < 1) {
182 assert(size % 4 == 0);
183 int* deps_data = reinterpret_cast<int*>(buf);
184 int out_id = deps_data[0];
185 int mtime = deps_data[1];
187 int deps_count = (size / 4) - 2;
189 Deps* deps = new Deps(mtime, deps_count);
190 for (int i = 0; i < deps_count; ++i) {
191 assert(deps_data[i] < (int)nodes_.size());
192 assert(nodes_[deps_data[i]]);
193 deps->nodes[i] = nodes_[deps_data[i]];
196 if (UpdateDeps(out_id, deps))
197 ++dead_record_count_;
199 StringPiece path(buf, size);
200 Node* node = state->GetNode(path);
201 assert(node->id() < 0);
202 node->set_id(nodes_.size());
203 nodes_.push_back(node);
208 // An error occurred while loading; try to recover by truncating the
209 // file to the last fully-read record.
211 *err = strerror(ferror(f));
213 *err = "premature end of file";
217 if (!Truncate(path.c_str(), offset, err))
220 // The truncate succeeded; we'll just report the load error as a
221 // warning because the build can proceed.
222 *err += "; recovering";
231 DepsLog::Deps* DepsLog::GetDeps(Node* node) {
232 // Abort if the node has no id (never referenced in the deps) or if
233 // there's no deps recorded for the node.
234 if (node->id() < 0 || node->id() >= (int)deps_.size())
236 return deps_[node->id()];
239 bool DepsLog::Recompact(const string& path, string* err) {
240 METRIC_RECORD(".ninja_deps recompact");
241 printf("Recompacting deps...\n");
243 string temp_path = path + ".recompact";
245 // OpenForWrite() opens for append. Make sure it's not appending to a
246 // left-over file from a previous recompaction attempt that crashed somehow.
247 unlink(temp_path.c_str());
250 if (!new_log.OpenForWrite(temp_path, err))
253 // Clear all known ids so that new ones can be reassigned.
254 for (vector<Node*>::iterator i = nodes_.begin();
255 i != nodes_.end(); ++i) {
259 // Write out all deps again.
260 for (int old_id = 0; old_id < (int)deps_.size(); ++old_id) {
261 Deps* deps = deps_[old_id];
262 if (!deps) continue; // If nodes_[old_id] is a leaf, it has no deps.
264 if (!new_log.RecordDeps(nodes_[old_id], deps->mtime,
265 deps->node_count, deps->nodes)) {
273 if (unlink(path.c_str()) < 0) {
274 *err = strerror(errno);
278 if (rename(temp_path.c_str(), path.c_str()) < 0) {
279 *err = strerror(errno);
286 bool DepsLog::UpdateDeps(int out_id, Deps* deps) {
287 if (out_id >= (int)deps_.size())
288 deps_.resize(out_id + 1);
290 bool delete_old = deps_[out_id] != NULL;
292 delete deps_[out_id];
293 deps_[out_id] = deps;
297 bool DepsLog::RecordId(Node* node) {
298 uint16_t size = (uint16_t)node->path().size();
299 fwrite(&size, 2, 1, file_);
300 fwrite(node->path().data(), node->path().size(), 1, file_);
302 node->set_id(nodes_.size());
303 nodes_.push_back(node);