[BlobAsync] Disk support for blob storage

content/browser/blob_storage/chrome_blob_storage_context.cc

Index: content/browser/blob_storage/chrome_blob_storage_context.cc
diff --git a/content/browser/blob_storage/chrome_blob_storage_context.cc b/content/browser/blob_storage/chrome_blob_storage_context.cc
index 533d3f10e222532aaa763dc26afc2df05a448995..8d0a652ee91394283e63234e72d96764b99c0069 100644
--- a/content/browser/blob_storage/chrome_blob_storage_context.cc
+++ b/content/browser/blob_storage/chrome_blob_storage_context.cc
@@ -7,7 +7,13 @@
 #include <utility>
 
 #include "base/bind.h"
+#include "base/files/file.h"
+#include "base/files/file_enumerator.h"
+#include "base/files/file_util.h"
 #include "base/guid.h"
+#include "base/metrics/histogram_macros.h"
+#include "base/single_thread_task_runner.h"
+#include "base/task_runner.h"
 #include "content/public/browser/blob_handle.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
@@ -15,12 +21,47 @@
 #include "storage/browser/blob/blob_data_handle.h"
 #include "storage/browser/blob/blob_storage_context.h"
 
+using base::FilePath;
 using base::UserDataAdapter;
 using storage::BlobStorageContext;
 
 namespace content {
 
 namespace {
+const char kBlobStorageParentDirectory[] = "blob_storage";
+
+void CreateBlobDirectory(const FilePath& blob_storage_dir,
+                         scoped_refptr<base::TaskRunner> io_runner,
+                         const base::Closure& done) {
+  base::File::Error error;
+  bool success = base::CreateDirectoryAndGetError(blob_storage_dir, &error);
+  LOCAL_HISTOGRAM_BOOLEAN("Storage.Blob.DirectorySuccess", success);
+  if (!success) {
+    LOCAL_HISTOGRAM_ENUMERATION("Storage.Blob.DirectorySuccess.Error", -error,
+                                -base::File::FILE_ERROR_MAX);
+  } else {
+    io_runner->PostTask(FROM_HERE, done);
+  }
+}
+
+// Removes all folders in the parent directory except for the
+// |current_run_dir| folder. If this path is empty, then we delete all folders.
+void RemoveOldBlobStorageDirectories(const FilePath& blob_storage_parent,
+                                     const FilePath& current_run_dir) {
+  if (!base::DirectoryExists(blob_storage_parent)) {
+    return;
+  }
+  base::FileEnumerator enumerator(blob_storage_parent, false,
+                                  base::FileEnumerator::DIRECTORIES);
+  std::vector<std::string> components;
+  bool success = true;
+  for (base::FilePath name = enumerator.Next(); !name.empty();
+       name = enumerator.Next()) {
+    if (current_run_dir.empty() || name != current_run_dir)
+      success &= base::DeleteFile(name, true);
+  }
+  LOCAL_HISTOGRAM_BOOLEAN("Storage.Blob.CleanupSuccess", success);
+}
 
 const char kBlobStorageContextKeyName[] = "content_blob_storage_context";
 
@@ -49,12 +90,44 @@ ChromeBlobStorageContext* ChromeBlobStorageContext::GetFor(
     context->SetUserData(
         kBlobStorageContextKeyName,
         new UserDataAdapter<ChromeBlobStorageContext>(blob.get()));
+
     // Check first to avoid memory leak in unittests.
-    if (BrowserThread::IsMessageLoopValid(BrowserThread::IO)) {
+    bool io_thread_valid = BrowserThread::IsMessageLoopValid(BrowserThread::IO);
+    if (io_thread_valid) {
       BrowserThread::PostTask(
           BrowserThread::IO, FROM_HERE,
           base::Bind(&ChromeBlobStorageContext::InitializeOnIOThread, blob));
     }
+
+    // If we're not incognito mode, schedule all of our file tasks to enable
+    // disk on the storage context.
+    if (!context->IsOffTheRecord() && io_thread_valid &&
+        BrowserThread::IsMessageLoopValid(BrowserThread::FILE)) {
+      // Resolve our storage directories.
+      base::FilePath blob_storage_parent =
+          context->GetPath().Append(kBlobStorageParentDirectory);
+      base::FilePath blob_storage_dir =
+          blob_storage_parent.Append(base::GenerateGUID());
+
+      scoped_refptr<base::SingleThreadTaskRunner> io_runner =
+          BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO);
+      scoped_refptr<base::SingleThreadTaskRunner> file_runner =
+          BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE);
+
+      // This creates our directory and calls |OnBlobDirectoryCreated| if we're
+      // successful.
+      BrowserThread::PostAfterStartupTask(
+          FROM_HERE, file_runner,
+          base::Bind(
+              &CreateBlobDirectory, blob_storage_dir, io_runner,
+              base::Bind(&ChromeBlobStorageContext::OnBlobDirectoryCreated,
+                         blob, blob_storage_dir)));
+      // Removes our old blob directories if they exist.
+      BrowserThread::PostAfterStartupTask(
+          FROM_HERE, file_runner,
+          base::Bind(&RemoveOldBlobStorageDirectories, blob_storage_parent,
+                     blob_storage_dir));
+    }
   }
 
   return UserDataAdapter<ChromeBlobStorageContext>::Get(
@@ -64,6 +137,13 @@ ChromeBlobStorageContext* ChromeBlobStorageContext::GetFor(
 void ChromeBlobStorageContext::InitializeOnIOThread() {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   context_.reset(new BlobStorageContext());
+  if (!blob_storage_dir_.empty()) {
+    // This happens if we create our blob storage folder before this method is
+    // called, so we enable disk here.
+    context_->EnableDisk(
+        blob_storage_dir_,
+        BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE));
+  }
 }
 
 std::unique_ptr<BlobHandle> ChromeBlobStorageContext::CreateMemoryBackedBlob(
@@ -109,6 +189,13 @@ std::unique_ptr<BlobHandle> ChromeBlobStorageContext::CreateFileBackedBlob(
 ChromeBlobStorageContext::~ChromeBlobStorageContext() {}
 
 void ChromeBlobStorageContext::DeleteOnCorrectThread() const {
+  // Schedule a task to delete all blob directories.
+  if (!blob_storage_dir_.empty()) {
+    BrowserThread::PostTask(
+        BrowserThread::FILE, FROM_HERE,
+        base::Bind(&RemoveOldBlobStorageDirectories,
+                   blob_storage_dir_.DirName(), base::FilePath()));
+  }
   if (BrowserThread::IsMessageLoopValid(BrowserThread::IO) &&
       !BrowserThread::CurrentlyOn(BrowserThread::IO)) {
     BrowserThread::DeleteSoon(BrowserThread::IO, FROM_HERE, this);
@@ -117,4 +204,17 @@ void ChromeBlobStorageContext::DeleteOnCorrectThread() const {
   delete this;
 }
 
+void ChromeBlobStorageContext::OnBlobDirectoryCreated(
+    const base::FilePath& blob_storage_directory) {
+  LOG(ERROR) << "Blob directory successfully created "
+             << blob_storage_directory.value();
+  DCHECK(blob_storage_dir_.empty());
+  blob_storage_dir_ = blob_storage_directory;
+  if (context_) {
+    context_->EnableDisk(
+        blob_storage_dir_,
+        BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE));
+  }
+}
+
 }  // namespace content