Simple PMP reader to parse Picasa's metadata

webkit/fileapi/media/picasa/pmp_column_reader_unittest.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 <algorithm>
+#include <vector>
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "webkit/fileapi/media/picasa/pmp_column_reader.h"
+#include "webkit/fileapi/media/picasa/pmp_constants.h"
+
+namespace {
+
+using fileapi::PmpColumnReader;
+
+// Return a vector so we don't have to worry about memory management.
+std::vector<uint8> MakeHeader(const uint16 field_type, const uint32 row_count) {
+  std::vector<uint8> header(fileapi::kPmpHeaderSize);
+
+  // Copy in magic bytes.
+  memcpy(&header[0],  fileapi::kPmpMagicO0S4, 4);
+  memcpy(&header[6],  fileapi::kPmpMagicO6S2, 2);
+  memcpy(&header[8],  fileapi::kPmpMagicO8S4, 4);
+  memcpy(&header[14], fileapi::kPmpMagicO14S2, 2);
+
+  // Copy in field type.
+  memcpy(&header[fileapi::kPmpFieldTypeFirstOffset],  &field_type, 2);
+  memcpy(&header[fileapi::kPmpFieldTypeSecondOffset], &field_type, 2);
+
+  // Copy in row count.
+  memcpy(&header[fileapi::kPmpRowCountOffset], &row_count, 4);
+
+  return header;
+}
+
+// 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 strings.
+// Given a vector of strings, returns a vector of all the characters in strings.
+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;
+}
+
+std::vector<uint8> Combined(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;
+}
+
+// Overridden version of Read method to make test code templatable.
+bool DoRead(const PmpColumnReader* reader, uint32 row, std::string* target) {
+  return reader->ReadString(row, target);
+}
+
+bool DoRead(const PmpColumnReader* reader, uint32 row, uint32* target) {
+  return reader->ReadUInt32(row, target);
+}
+
+bool DoRead(const PmpColumnReader* reader, uint32 row, double* target) {
+  return reader->ReadDouble64(row, target);
+}
+
+bool DoRead(const PmpColumnReader* reader, uint32 row, uint8* target) {
+  return reader->ReadUInt8(row, target);
+}
+
+bool DoRead(const PmpColumnReader* reader, uint32 row, uint64* target) {
+  return reader->ReadUInt64(row, target);
+}
+
+// TestValid
+template<class T>
+void TestValid(PmpColumnReader* reader, const uint16 field_type,
+               const std::vector<T>& elems) {
+  uint32 rows_read = 0xFF;
+
+  std::vector<uint8> data = Combined(MakeHeader(field_type, elems.size()),
+                                     Flatten(elems));
+  EXPECT_TRUE(reader->ReadFromMemory(&rows_read, &data[0], data.size()));
+  EXPECT_EQ(rows_read, elems.size());
+
+  for(uint32 i = 0; i < elems.size(); i++) {
+    T target;
+    EXPECT_TRUE(DoRead(reader, i, &target));
+    EXPECT_EQ(target, elems[i]);
+  }
+}
+
+template<class T>
+void TestMalformed(PmpColumnReader* reader, const uint16 field_type,
+                   const std::vector<T>& elems) {
+
+  std::vector<uint8> data_too_few_declared_rows =
+      Combined(MakeHeader(field_type, elems.size()-1), Flatten(elems));
+  EXPECT_FALSE(reader->ReadFromMemory(NULL,
+                                      &data_too_few_declared_rows[0],
+                                      data_too_few_declared_rows.size()));
+
+  std::vector<uint8> data_too_many_declared_rows =
+      Combined(MakeHeader(field_type, elems.size()+1), Flatten(elems));
+  EXPECT_FALSE(reader->ReadFromMemory(NULL,
+                                      &data_too_many_declared_rows[0],
+                                      data_too_many_declared_rows.size()));
+
+  std::vector<uint8> data_truncated =
+      Combined(MakeHeader(field_type, elems.size()), Flatten(elems));
+  data_truncated.resize(data_truncated.size()-10);
+
+  EXPECT_FALSE(reader->ReadFromMemory(NULL, &data_truncated[0],
+                                      data_truncated.size()));
+
+  std::vector<uint8> data_padded =
+      Combined(MakeHeader(field_type, elems.size()), Flatten(elems));
+  data_padded.resize(data_padded.size()+10);
+  EXPECT_FALSE(reader->ReadFromMemory(NULL, &data_padded[0],
+                                      data_padded.size()));
+}
+
+template<class T>
+void TestPrimitives(const uint16 field_type) {
+  PmpColumnReader reader("testcolumn");
+
+  // Make an ascending vector of the primitive.
+  uint32 n = 100;
+  std::vector<T> data(n, 0);
+  for(uint32 i = 0; i < n; i++) {
+    data[i] = i*3;
+  }
+
+  TestValid<T>(&reader, field_type, data);
+  TestMalformed<T>(&reader, field_type, data);
+}
+
+
+TEST(PmpColumnReaderTest, HeaderParsingAndValidation) {
+  PmpColumnReader reader("testcolumn");
+
+  // Good header.
+  uint32 rows_read = 0xFF;
+  std::vector<uint8> good_header = MakeHeader(0x00, 0);
+  EXPECT_TRUE(reader.ReadFromMemory(&rows_read, &good_header[0],
+                                    good_header.size()));
+  EXPECT_EQ(rows_read, 0U) << "Read non-zero rows from header-only data.";
+
+  // Botch up elements of the header.
+  std::vector<uint8> bad_magic_byte = MakeHeader(0x00, 0);
+  bad_magic_byte[0] = 0xff;
+  EXPECT_FALSE(reader.ReadFromMemory(NULL, &bad_magic_byte[0],
+                                     bad_magic_byte.size()));
+
+  // Corrupt means the type fields don't agree.
+  std::vector<uint8> corrupt_type = MakeHeader(0x00, 0);
+  corrupt_type[fileapi::kPmpFieldTypeFirstOffset] = 0xff;
+  EXPECT_FALSE(reader.ReadFromMemory(NULL, &corrupt_type[0],
+                                     corrupt_type.size()));
+
+  std::vector<uint8> invalid_type = MakeHeader(0x00, 0);
+  invalid_type[fileapi::kPmpFieldTypeFirstOffset] = 0xff;
+  invalid_type[fileapi::kPmpFieldTypeSecondOffset] = 0xff;
+  EXPECT_FALSE(reader.ReadFromMemory(NULL, &invalid_type[0],
+                                     invalid_type.size()));
+
+  std::vector<uint8> incomplete_header = MakeHeader(0x00, 0);
+  incomplete_header.resize(10);
+  EXPECT_FALSE(reader.ReadFromMemory(NULL, &incomplete_header[0],
+                                     incomplete_header.size()));
+}
+
+TEST(PmpColumnReaderTest, StringParsing) {
+  PmpColumnReader reader("testcolumn");
+
+  std::vector<std::string> empty_strings(100, "");
+
+  // Test empty strings read okay.
+  TestValid(&reader, fileapi::kPmpFieldTypeString, empty_strings);
+
+  std::vector<std::string> mixed_strings;
+  mixed_strings.push_back("");
+  mixed_strings.push_back("Hello");
+  mixed_strings.push_back("World");
+  mixed_strings.push_back("");
+  mixed_strings.push_back("123123");
+  mixed_strings.push_back("Q");
+  mixed_strings.push_back("");
+
+  // Test that a mixed set of strings read correctly.
+  TestValid(&reader, fileapi::kPmpFieldTypeString, mixed_strings);
+
+  // Test with the data messed up in a variety of ways.
+  TestMalformed(&reader, fileapi::kPmpFieldTypeString, mixed_strings);
+}
+
+TEST(PmpColumnReaderTest, PrimitiveParsing) {
+  TestPrimitives<uint32>(fileapi::kPmpFieldTypeUInt32);
+  TestPrimitives<double>(fileapi::kPmpFieldTypeDouble64);
+  TestPrimitives<uint8>(fileapi::kPmpFieldTypeUInt8);
+  TestPrimitives<uint64>(fileapi::kPmpFieldTypeUInt64);
+}
+
+}  // namespace