blob: 0bb96f3759e180d9ab7f0f568b12ebdf26a83529 [file] [log] [blame]
// 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"
// 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;
}
file_ = fopen(path.c_str(), "ab");
if (!file_) {
*err = strerror(errno);
return false;
}
// Set the buffer size to this and flush the file buffer after every record
// to make sure records aren't written partially.
setvbuf(file_, NULL, _IOFBF, kMaxRecordSize + 1);
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) {
*err = strerror(errno);
return false;
}
if (fwrite(&kCurrentVersion, 4, 1, file_) < 1) {
*err = strerror(errno);
return false;
}
}
if (fflush(file_) != 0) {
*err = strerror(errno);
return false;
}
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;
}
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() {
if (file_)
fclose(file_);
file_ = NULL;
}
bool 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 true;
*err = strerror(errno);
return false;
}
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 true;
}
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 false;
// The truncate succeeded; we'll just report the load error as a
// warning because the build can proceed.
*err += "; recovering";
return true;
}
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 true;
}
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()];
}
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 (fwrite(&size, 4, 1, file_) < 1)
return false;
if (fwrite(node->path().data(), path_size, 1, file_) < 1) {
assert(node->path().size() > 0);
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;
}