PicasaAlbumTableReader for Media Galleries API

chrome/browser/media_galleries/fileapi/picasa/pmp_table_reader.cc

 // Copyright 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 "chrome/browser/media_galleries/fileapi/picasa/pmp_table_reader.h"
 
 #include <algorithm>
 
 #include "base/file_util.h"
-#include "base/files/file_path.h"
 #include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/threading/thread_restrictions.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/media_galleries/fileapi/picasa/pmp_column_reader.h"
-#include "chrome/browser/media_galleries/fileapi/picasa/pmp_constants.h"
 
 namespace picasaimport {
 
 namespace {
 
 COMPILE_ASSERT(sizeof(double) == 8, double_must_be_8_bytes_long);
 
 }  // namespace
 
-PmpTableReader::PmpTableReader() : column_readers_(), max_row_count_(0) { }
+PmpTableReader::PmpTableReader(const std::string& table_name,
+                               const base::FilePath& directory_path)
+    : initialized_(false),
+      table_name_(table_name),
+      directory_path_(directory_path),
+      max_row_count_(0) {
+  base::ThreadRestrictions::AssertIOAllowed();
 
-PmpTableReader::~PmpTableReader() { }
+  if (!file_util::DirectoryExists(directory_path_))
+    return;
 
-bool PmpTableReader::Init(const std::string& table_name,
-                          const base::FilePath& directory_path,
-                          const std::vector<std::string>& columns) {
-  DCHECK(!columns.empty());
+  std::string indicator_file_name = table_name_ + "_0";
 
-  if (!column_readers_.empty())
-    return false;
-
-  if (!file_util::DirectoryExists(directory_path))
-    return false;
-
-  std::string table_prefix = table_name + "_";
-  std::string indicator_file_name = table_prefix + "0";
-
-  base::FilePath indicator_file = directory_path.Append(
+  base::FilePath indicator_file = directory_path_.Append(
       base::FilePath::FromUTF8Unsafe(indicator_file_name));
 
   // Look for the indicator_file file, indicating table existence.
-  if (!file_util::PathExists(indicator_file) ||
-      file_util::DirectoryExists(indicator_file)) {
-    return false;
-  }
+  initialized_ = file_util::PathExists(indicator_file) &&
+                 !file_util::DirectoryExists(indicator_file);
+}
 
-  ScopedVector<PmpColumnReader> column_readers;
-  uint32 max_row_count = 0;
+PmpTableReader::~PmpTableReader() {}
 
-  for (std::vector<std::string>::const_iterator it = columns.begin();
-       it != columns.end(); ++it) {
-    std::string filename = table_prefix + *it + "." + kPmpExtension;
+const PmpColumnReader* PmpTableReader::AddColumn(
+    const std::string& column_name, const PmpFieldType expected_type) {
+  if (!initialized_)
+    return NULL;
 
-    base::FilePath column_file_path = directory_path.Append(
+  std::string filename = table_name_ + "_" + column_name + "." + kPmpExtension;
+
+  base::FilePath column_file_path = directory_path_.Append(
         base::FilePath::FromUTF8Unsafe(filename));
+  scoped_ptr<PmpColumnReader> column_reader(new PmpColumnReader());
 
-    PmpColumnReader* column_reader = new PmpColumnReader();
-    column_readers.push_back(column_reader);
+  uint32 row_count;
+  if (!column_reader->Init(column_file_path, expected_type, &row_count))
+    return NULL;
 
-    uint32 row_cnt;
+  column_readers_.push_back(column_reader.release());
+  column_map_[column_name] = column_readers_.back();
 
-    if (!column_reader->Init(column_file_path, &row_cnt))
-      return false;
+  max_row_count_ = std::max(max_row_count_, row_count);
 
-    max_row_count = std::max(max_row_count, row_cnt);
-  }
-
-  column_readers_ = column_readers.Pass();
-  max_row_count_ = max_row_count;
-
-  return true;
+  return column_readers_.back();
 }
 
 uint32 PmpTableReader::RowCount() const {
   return max_row_count_;
 }
 
-std::vector<const PmpColumnReader*> PmpTableReader::GetColumns() const {
-  std::vector<const PmpColumnReader*> readers(
-      column_readers_.begin(), column_readers_.end());
-  return readers;
+std::map<std::string, const PmpColumnReader*> PmpTableReader::Columns() const {
+  return column_map_;
 }
 
 }  // namespace picasaimport