Simple PMP reader to parse Picasa's metadata

webkit/fileapi/media/picasa/pmp_test_helper.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 "webkit/fileapi/media/picasa/pmp_test_helper.h"
+
+#include <algorithm>
+#include <iterator>
+
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "base/utf_string_conversions.h"
+#include "webkit/fileapi/media/picasa/pmp_column_reader.h"
+
+namespace picasaimport {
+
+namespace {
+
+bool WriteToFile(const base::FilePath& path, std::vector<uint8> data) {
+  // Cast for usage in WriteFile function
+  const char* data_char = reinterpret_cast<const char*>(&data[0]);
+  size_t bytes_written = file_util::WriteFile(path, data_char, data.size());
+  return (bytes_written == data.size());
+}
+
+// Flatten a vector of elements into an array of bytes.
+template<class T>
+std::vector<uint8> Flatten(const std::vector<T>& elems) {
+  const uint8* elems0 = reinterpret_cast<const uint8*>(&elems[0]);
+  std::vector<uint8> data_body(elems0, elems0 + sizeof(T)*elems.size());
+
+  return data_body;
+}
+
+// Custom specialization for std::string.
+template<>
+std::vector<uint8> Flatten(const std::vector<std::string>& strings) {
+  std::vector<uint8> totalchars;
+
+  for(std::vector<std::string>::const_iterator it = strings.begin();
+      it != strings.end(); ++it) {
+    std::copy(it->begin(), it->end(), std::back_inserter(totalchars));
+    totalchars.push_back('\0'); // Add the null termination too.
+  }
+
+  return totalchars;
+}
+
+// Returns a new vector with the concatenated contents of |a| and |b|.
+std::vector<uint8> CombinedVectors(const std::vector<uint8>& a,
+                                   const std::vector<uint8>& b) {
+  std::vector<uint8> total;
+
+  std::copy(a.begin(), a.end(), std::back_inserter(total));
+  std::copy(b.begin(), b.end(), std::back_inserter(total));
+
+  return total;
+}
+
+}  // namespace
+
+PmpTestHelper::PmpTestHelper() { }
+
+bool PmpTestHelper::Init() {
+  return temp_dir_.CreateUniqueTempDir();
+}
+
+base::FilePath PmpTestHelper::GetTempDirPath() {
+  DCHECK(temp_dir_.IsValid());
+  return temp_dir_.path();
+}
+
+template<class T>
+bool PmpTestHelper::WriteColumnFileFromVector(
+    const std::string& table_name, const std::string& column_name,
+    const PmpFieldType field_type, const std::vector<T>& elements_vector) {
+  DCHECK(temp_dir_.IsValid());
+
+  std::string file_name = table_name + "_" + column_name + "." + kPmpExtension;
+
+  base::FilePath path = temp_dir_.path().Append(
+      base::FilePath::FromUTF8Unsafe(file_name));
+
+  std::vector<uint8> data = PmpTestHelper::MakeHeaderAndBody(
+      field_type, elements_vector.size(), elements_vector);
+
+  return WriteToFile(path, data);
+}
+
+// Explicit Instantiation for all the valid types.
+template bool PmpTestHelper::WriteColumnFileFromVector<std::string>(
+    const std::string&, const std::string&, const PmpFieldType,
+    const std::vector<std::string>&);
+template bool PmpTestHelper::WriteColumnFileFromVector<uint32>(
+    const std::string&, const std::string&, const PmpFieldType,
+    const std::vector<uint32>&);
+template bool PmpTestHelper::WriteColumnFileFromVector<double>(
+    const std::string&, const std::string&, const PmpFieldType,
+    const std::vector<double>&);
+template bool PmpTestHelper::WriteColumnFileFromVector<uint8>(
+    const std::string&, const std::string&, const PmpFieldType,
+    const std::vector<uint8>&);
+template bool PmpTestHelper::WriteColumnFileFromVector<uint64>(
+    const std::string&, const std::string&, const PmpFieldType,
+    const std::vector<uint64>&);
+
+bool PmpTestHelper::InitColumnReaderFromBytes(
+    PmpColumnReader* const reader, const std::vector<uint8>& data,
+    uint32* rows_read) {
+  DCHECK(temp_dir_.IsValid());
+
+  base::FilePath temp_path;
+
+  if (!file_util::CreateTemporaryFileInDir(temp_dir_.path(), &temp_path) ||
+      !WriteToFile(temp_path, data)) {
+    return false;
+  }
+
+  bool success = reader->Init(temp_path, rows_read);
+
+  file_util::Delete(temp_path, true);
+
+  return success;
+
+}
+
+// Return a vector so we don't have to worry about memory management.
+std::vector<uint8> PmpTestHelper::MakeHeader(const PmpFieldType field_type,
+                                             const uint32 row_count) {
+  std::vector<uint8> header(picasaimport::kPmpHeaderSize);
+
+  // Copy in magic bytes.
+  memcpy(&header[picasaimport::kPmpMagic1Offset], &picasaimport::kPmpMagic1,
+         sizeof(picasaimport::kPmpMagic1));
+  memcpy(&header[picasaimport::kPmpMagic2Offset], &picasaimport::kPmpMagic2,
+         sizeof(picasaimport::kPmpMagic2));
+  memcpy(&header[picasaimport::kPmpMagic3Offset], &picasaimport::kPmpMagic3,
+         sizeof(picasaimport::kPmpMagic3));
+  memcpy(&header[picasaimport::kPmpMagic4Offset], &picasaimport::kPmpMagic4,
+         sizeof(picasaimport::kPmpMagic4));
+
+  // Copy in field type.
+  memcpy(&header[picasaimport::kPmpFieldType1Offset], &field_type, 2);
+  memcpy(&header[picasaimport::kPmpFieldType2Offset], &field_type, 2);
+
+  // Copy in row count.
+  memcpy(&header[picasaimport::kPmpRowCountOffset], &row_count, 4);
+
+  return header;
+}
+
+template<class T>
+std::vector<uint8> PmpTestHelper::MakeHeaderAndBody(
+    const PmpFieldType field_type, const uint32 row_count,
+    const std::vector<T>& elems) {
+  return CombinedVectors(PmpTestHelper::MakeHeader(field_type, row_count),
+                         Flatten(elems));
+}
+
+// Explicit Instantiation for all the valid types.
+template std::vector<uint8> PmpTestHelper::MakeHeaderAndBody<std::string>(
+    const PmpFieldType, const uint32, const std::vector<std::string>&);
+template std::vector<uint8> PmpTestHelper::MakeHeaderAndBody<uint32>(
+    const PmpFieldType, const uint32, const std::vector<uint32>&);
+template std::vector<uint8> PmpTestHelper::MakeHeaderAndBody<double>(
+    const PmpFieldType, const uint32, const std::vector<double>&);
+template std::vector<uint8> PmpTestHelper::MakeHeaderAndBody<uint8>(
+    const PmpFieldType, const uint32, const std::vector<uint8>&);
+template std::vector<uint8> PmpTestHelper::MakeHeaderAndBody<uint64>(
+    const PmpFieldType, const uint32, const std::vector<uint64>&);
+
+}  // namespace picasaimport