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// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "content/browser/indexed_db/indexed_db_cursor.h"
#include <stddef.h>
#include <utility>
#include <vector>
#include "base/bind.h"
#include "base/logging.h"
#include "content/browser/indexed_db/indexed_db_callbacks.h"
#include "content/browser/indexed_db/indexed_db_database_error.h"
#include "content/browser/indexed_db/indexed_db_tracing.h"
#include "content/browser/indexed_db/indexed_db_transaction.h"
#include "content/browser/indexed_db/indexed_db_value.h"
namespace content {
IndexedDBCursor::IndexedDBCursor(
std::unique_ptr<IndexedDBBackingStore::Cursor> cursor,
indexed_db::CursorType cursor_type,
blink::WebIDBTaskType task_type,
IndexedDBTransaction* transaction)
: task_type_(task_type),
cursor_type_(cursor_type),
transaction_(transaction),
cursor_(std::move(cursor)),
closed_(false) {
transaction_->RegisterOpenCursor(this);
}
IndexedDBCursor::~IndexedDBCursor() {
transaction_->UnregisterOpenCursor(this);
}
void IndexedDBCursor::Continue(std::unique_ptr<IndexedDBKey> key,
std::unique_ptr<IndexedDBKey> primary_key,
scoped_refptr<IndexedDBCallbacks> callbacks) {
IDB_TRACE("IndexedDBCursor::Continue");
transaction_->ScheduleTask(
task_type_,
base::Bind(&IndexedDBCursor::CursorIterationOperation,
this,
base::Passed(&key),
base::Passed(&primary_key),
callbacks));
}
void IndexedDBCursor::Advance(uint32_t count,
scoped_refptr<IndexedDBCallbacks> callbacks) {
IDB_TRACE("IndexedDBCursor::Advance");
transaction_->ScheduleTask(
task_type_,
base::Bind(
&IndexedDBCursor::CursorAdvanceOperation, this, count, callbacks));
}
void IndexedDBCursor::CursorAdvanceOperation(
uint32_t count,
scoped_refptr<IndexedDBCallbacks> callbacks,
IndexedDBTransaction* /*transaction*/) {
IDB_TRACE("IndexedDBCursor::CursorAdvanceOperation");
leveldb::Status s;
// TODO(cmumford): Handle this error (crbug.com/363397). Although this will
// properly fail, caller will not know why, and any corruption
// will be ignored.
if (!cursor_ || !cursor_->Advance(count, &s)) {
cursor_.reset();
callbacks->OnSuccess(nullptr);
return;
}
callbacks->OnSuccess(key(), primary_key(), Value());
}
void IndexedDBCursor::CursorIterationOperation(
std::unique_ptr<IndexedDBKey> key,
std::unique_ptr<IndexedDBKey> primary_key,
scoped_refptr<IndexedDBCallbacks> callbacks,
IndexedDBTransaction* /*transaction*/) {
IDB_TRACE("IndexedDBCursor::CursorIterationOperation");
leveldb::Status s;
// TODO(cmumford): Handle this error (crbug.com/363397). Although this will
// properly fail, caller will not know why, and any corruption
// will be ignored.
if (!cursor_ || !cursor_->Continue(key.get(),
primary_key.get(),
IndexedDBBackingStore::Cursor::SEEK,
&s) || !s.ok()) {
cursor_.reset();
callbacks->OnSuccess(nullptr);
return;
}
callbacks->OnSuccess(this->key(), this->primary_key(), Value());
}
void IndexedDBCursor::PrefetchContinue(
int number_to_fetch,
scoped_refptr<IndexedDBCallbacks> callbacks) {
IDB_TRACE("IndexedDBCursor::PrefetchContinue");
transaction_->ScheduleTask(
task_type_,
base::Bind(&IndexedDBCursor::CursorPrefetchIterationOperation,
this,
number_to_fetch,
callbacks));
}
void IndexedDBCursor::CursorPrefetchIterationOperation(
int number_to_fetch,
scoped_refptr<IndexedDBCallbacks> callbacks,
IndexedDBTransaction* /*transaction*/) {
IDB_TRACE("IndexedDBCursor::CursorPrefetchIterationOperation");
std::vector<IndexedDBKey> found_keys;
std::vector<IndexedDBKey> found_primary_keys;
std::vector<IndexedDBValue> found_values;
saved_cursor_.reset();
// TODO(cmumford): Use IPC::Channel::kMaximumMessageSize
const size_t max_size_estimate = 10 * 1024 * 1024;
size_t size_estimate = 0;
leveldb::Status s;
// TODO(cmumford): Handle this error (crbug.com/363397). Although this will
// properly fail, caller will not know why, and any corruption
// will be ignored.
for (int i = 0; i < number_to_fetch; ++i) {
if (!cursor_ || !cursor_->Continue(&s)) {
cursor_.reset();
break;
}
if (i == 0) {
// First prefetched result is always used, so that's the position
// a cursor should be reset to if the prefetch is invalidated.
saved_cursor_ = cursor_->Clone();
}
found_keys.push_back(cursor_->key());
found_primary_keys.push_back(cursor_->primary_key());
switch (cursor_type_) {
case indexed_db::CURSOR_KEY_ONLY:
found_values.push_back(IndexedDBValue());
break;
case indexed_db::CURSOR_KEY_AND_VALUE: {
IndexedDBValue value;
value.swap(*cursor_->value());
size_estimate += value.SizeEstimate();
found_values.push_back(value);
break;
}
default:
NOTREACHED();
}
size_estimate += cursor_->key().size_estimate();
size_estimate += cursor_->primary_key().size_estimate();
if (size_estimate > max_size_estimate)
break;
}
if (found_keys.empty()) {
callbacks->OnSuccess(nullptr);
return;
}
callbacks->OnSuccessWithPrefetch(
found_keys, found_primary_keys, &found_values);
}
leveldb::Status IndexedDBCursor::PrefetchReset(int used_prefetches,
int /* unused_prefetches */) {
IDB_TRACE("IndexedDBCursor::PrefetchReset");
cursor_.swap(saved_cursor_);
saved_cursor_.reset();
leveldb::Status s;
if (closed_)
return s;
if (cursor_) {
// First prefetched result is always used.
DCHECK_GT(used_prefetches, 0);
for (int i = 0; i < used_prefetches - 1; ++i) {
bool ok = cursor_->Continue(&s);
DCHECK(ok);
}
}
return s;
}
void IndexedDBCursor::Close() {
IDB_TRACE("IndexedDBCursor::Close");
closed_ = true;
cursor_.reset();
saved_cursor_.reset();
}
} // namespace content
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