Revert of Replace system IO calls in chromecast/crash with Chrome utilities.

chromecast/crash/linux/dummy_minidump_generator.cc

Index: chromecast/crash/linux/dummy_minidump_generator.cc
diff --git a/chromecast/crash/linux/dummy_minidump_generator.cc b/chromecast/crash/linux/dummy_minidump_generator.cc
index a0cea9fef971f85c19f2e32d87afada760c37d8f..019febfc4970c92ce429ffd08da1ad08b715b419 100644
--- a/chromecast/crash/linux/dummy_minidump_generator.cc
+++ b/chromecast/crash/linux/dummy_minidump_generator.cc
@@ -4,11 +4,20 @@
 
 #include "chromecast/crash/linux/dummy_minidump_generator.h"
 
-#include "base/files/file_util.h"
+#include <stdio.h>
+#include <sys/stat.h>
+
+#include <vector>
+
 #include "base/logging.h"
-#include "base/threading/thread_restrictions.h"
 
 namespace chromecast {
+
+namespace {
+
+const int kBufferSize = 32768;
+
+}  // namespace
 
 DummyMinidumpGenerator::DummyMinidumpGenerator(
     const std::string& existing_minidump_path)
@@ -16,18 +25,75 @@
 }
 
 bool DummyMinidumpGenerator::Generate(const std::string& minidump_path) {
-  base::ThreadRestrictions::AssertIOAllowed();
+  // Use stdlib calls here to avoid potential IO restrictions on this thread.
 
   // Return false if the file does not exist.
-  if (!base::PathExists(base::FilePath(existing_minidump_path_))) {
-    LOG(ERROR) << existing_minidump_path_ << " does not exist.";
+  struct stat st;
+  if (stat(existing_minidump_path_.c_str(), &st) != 0) {
+    PLOG(ERROR) << existing_minidump_path_.c_str() << " does not exist: ";
     return false;
   }
 
   LOG(INFO) << "Moving minidump from " << existing_minidump_path_ << " to "
             << minidump_path << " for further uploading.";
-  return base::Move(base::FilePath(existing_minidump_path_),
-                    base::FilePath(minidump_path));
+
+  // Attempt to rename(). If this operation fails, the files are on different
+  // volumes. Fall back to a copy and delete.
+  if (rename(existing_minidump_path_.c_str(), minidump_path.c_str()) < 0) {
+    // Any errors will be logged within CopyAndDelete().
+    return CopyAndDelete(minidump_path);
+  }
+
+  return true;
+}
+
+bool DummyMinidumpGenerator::CopyAndDelete(const std::string& dest_path) {
+  FILE* src = fopen(existing_minidump_path_.c_str(), "r");
+  if (!src) {
+    PLOG(ERROR) << existing_minidump_path_ << " failed to open: ";
+    return false;
+  }
+
+  FILE* dest = fopen(dest_path.c_str(), "w");
+  if (!dest) {
+    PLOG(ERROR) << dest_path << " failed to open: ";
+    return false;
+  }
+
+  // Copy all bytes from |src| into |dest|.
+  std::vector<char> buffer(kBufferSize);
+  bool success = false;
+  while (!success) {
+    size_t bytes_read = fread(&buffer[0], 1, buffer.size(), src);
+    if (bytes_read < buffer.size()) {
+      if (feof(src)) {
+        success = true;
+      } else {
+        // An error occurred.
+        PLOG(ERROR) << "Error reading " << existing_minidump_path_ << ": ";
+        break;
+      }
+    }
+
+    size_t bytes_written = fwrite(&buffer[0], 1, bytes_read, dest);
+    if (bytes_written < bytes_read) {
+      // An error occurred.
+      PLOG(ERROR) << "Error writing to " << dest_path << ": ";
+      success = false;
+      break;
+    }
+  }
+
+  // Close both files.
+  fclose(src);
+  fclose(dest);
+
+  // Attempt to delete file at |existing_minidump_path_|. We should log this
+  // error, but the function should not fail if the file is not removed.
+  if (remove(existing_minidump_path_.c_str()) < 0)
+    PLOG(ERROR) << "Could not remove " << existing_minidump_path_ << ": ";
+
+  return success;
 }
 
 }  // namespace chromecast