add a class for logging builds (commands + timing)

1 files changed, 89 insertions, 0 deletions

diff --git a/src/build_log.cc b/src/build_log.cc
new file mode 100644
index 0000000..06db0e6
--- /dev/null
+++ b/src/build_log.cc
@@ -0,0 +1,89 @@
+#include "build_log.h"
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "ninja.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.
+// XXX figure out recompaction strategy
+
+bool BuildLog::OpenForWrite(const string& path, string* err) {
+  log_file_ = fopen(path.c_str(), "ab");
+  if (!log_file_) {
+    *err = strerror(errno);
+    return false;
+  }
+  setlinebuf(log_file_);
+  return true;
+}
+
+void BuildLog::RecordCommand(Edge* edge, int time_ms) {
+  const string command = edge->EvaluateCommand();
+  for (vector<Node*>::iterator out = edge->outputs_.begin();
+       out != edge->outputs_.end(); ++out) {
+    const string& path = (*out)->file_->path_;
+    Log::iterator i = log_.find(path);
+    LogEntry* log_entry;
+    if (i != log_.end()) {
+      log_entry = i->second;
+    } else {
+      log_entry = new LogEntry;
+      log_.insert(make_pair(path, log_entry));
+    }
+    log_entry->output = path;
+    log_entry->command = command;
+    log_entry->time_ms = time_ms;
+
+    fprintf(log_file_, "%d %s %s\n", time_ms, path.c_str(), command.c_str());
+  }
+}
+
+void BuildLog::Close() {
+  fclose(log_file_);
+  log_file_ = NULL;
+}
+
+// Load the on-disk log.
+bool BuildLog::Load(const string& path, string* err) {
+  FILE* file = fopen(path.c_str(), "r");
+  if (!file) {
+    *err = strerror(errno);
+    return false;
+  }
+
+  char buf[4 << 10];
+  while (fgets(buf, sizeof(buf), file)) {
+    char* start = buf;
+    char* end = strchr(start, ' ');
+    if (!end)
+      continue;
+
+    LogEntry* entry = new LogEntry;
+    *end = 0;
+    entry->time_ms = atoi(start);
+
+    start = end + 1;
+    end = strchr(start, ' ');
+    entry->output = string(start, end - start);
+
+    start = end + 1;
+    end = strchr(start, '\n');
+    entry->command = string(start, end - start);
+    log_.insert(make_pair(entry->output, entry));
+  }
+
+  return true;
+}
+
+// Lookup a previously-run command by its output path.
+BuildLog::LogEntry* BuildLog::LookupByOutput(const string& path) {
+  Log::iterator i = log_.find(path);
+  if (i != log_.end())
+    return i->second;
+  return NULL;
+}