Simple PMP reader to parse Picasa's metadata

webkit/fileapi/media/picasa/pmp_column_reader.h

Index: webkit/fileapi/media/picasa/pmp_column_reader.h
diff --git a/webkit/fileapi/media/picasa/pmp_column_reader.h b/webkit/fileapi/media/picasa/pmp_column_reader.h
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index 0000000000000000000000000000000000000000..126657421df75c498d7bc654e75380d7d2e9a6c1
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+++ b/webkit/fileapi/media/picasa/pmp_column_reader.h
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+// 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.
+
+#ifndef WEBKIT_FILEAPI_MEDIA_PICASA_PMP_COLUMN_READER_H_
+#define WEBKIT_FILEAPI_MEDIA_PICASA_PMP_COLUMN_READER_H_
+
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "webkit/fileapi/media/picasa/pmp_constants.h"
+#include "webkit/storage/webkit_storage_export.h"
+
+namespace base {
+class FilePath;
+}
+
+namespace picasaimport {
+
+// Reads a single PMP column from a file.
+class WEBKIT_STORAGE_EXPORT_PRIVATE PmpColumnReader {
+ public:
+  PmpColumnReader();
+  virtual ~PmpColumnReader();
+
+  // Returns true if read successfully.
+  // |rows_read| is undefined if returns false.
+  bool Init(const base::FilePath& filepath, uint32* rows_read);
+
+  // These functions read the value of that |row| into |result|.
+  // Functions return false if the column is of the wrong type or the row
+  // is out of range.
+  bool ReadString(const uint32 row, std::string* result) const;
+  bool ReadUInt32(const uint32 row, uint32* result) const;
+  bool ReadDouble64(const uint32 row, double* result) const;
+  bool ReadUInt8(const uint32 row, uint8* result) const;
+  bool ReadUInt64(const uint32 row, uint64* result) const;
+
+  // Returns the native encoding of field_type.
+  PmpFieldType field_type() const {
+    return field_type_;
+  }
+
+ private:
+  bool ParseData(uint32* rows_read);
+  // Returns the number of bytes parsed in the body, or, -1 on failure.
+  long IndexStrings();
+
+  // Source data
+  scoped_array<uint8> data_;
+  size_t length_;
+
+  // Header data
+  PmpFieldType field_type_;
+  uint32 rows_;
+
+  // Index of string start locations if fields are strings. Empty otherwise.
+  std::vector<const char*> strings_;
+
+  DISALLOW_COPY_AND_ASSIGN(PmpColumnReader);
+};
+
+}  // namespace picasaimport
+
+#endif  // WEBKIT_FILEAPI_MEDIA_PICASA_PMP_COLUMN_READER_H_