1 files changed, 161 insertions, 0 deletions
diff --git a/src/tiff_directory/tiff_directory.h b/src/tiff_directory/tiff_directory.h
new file mode 100755
index 0000000..855adfc
--- /dev/null
+++ b/src/tiff_directory/tiff_directory.h
@@ -0,0 +1,161 @@
+// Copyright 2015 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// TiffDirectory contains an abstraction of an image file directory (IFD) as
+// proposed by the TIFF specification.
+
+#ifndef PIEX_TIFF_DIRECTORY_TIFF_DIRECTORY_H_
+#define PIEX_TIFF_DIRECTORY_TIFF_DIRECTORY_H_
+
+#include <cstdint>
+#include <map>
+#include <string>
+#include <vector>
+
+namespace piex {
+namespace tiff_directory {
+
+enum Endian {
+  kLittleEndian = 0,
+  kBigEndian = 1,
+};
+
+struct Rational {
+  std::uint32_t numerator;
+  std::uint32_t denominator;
+};
+
+struct SRational {
+  std::int32_t numerator;
+  std::int32_t denominator;
+};
+
+enum TiffTypes {
+  TIFF_TYPE_NONE = 0,
+  TIFF_TYPE_BYTE,      /* 8bit unsigned */
+  TIFF_TYPE_ASCII,     /* Ascii string (terminated by \0) */
+  TIFF_TYPE_SHORT,     /* 16bit unsigned  */
+  TIFF_TYPE_LONG,      /* 32bit unsigned  */
+  TIFF_TYPE_RATIONAL,  /* 32bit/32bit unsigned  */
+  TIFF_TYPE_SBYTE,     /* 8bit signed */
+  TIFF_TYPE_UNDEFINED, /* undefined (depend of tag) */
+  TIFF_TYPE_SSHORT,    /* 16bit signed*/
+  TIFF_TYPE_SLONG,     /* 32bit signed  */
+  TIFF_TYPE_SRATIONAL, /* 32bit/32bit signed */
+  TIFF_TYPE_FLOAT,     /* 32-bit IEEE float */
+  TIFF_TYPE_DOUBLE,    /* 64-bit IEEE float */
+  TIFF_IFD,            /* IFD type */
+};
+
+// The TiffDirectory class stores all information necessary to interpret TIFF
+// tags and manages also potential sub directories.
+class TiffDirectory {
+ public:
+  typedef std::uint32_t Tag;
+  typedef std::uint32_t Type;
+
+  explicit TiffDirectory(Endian endianness);
+
+  // Returns true if the directory contains the specified tag.
+  bool Has(const Tag tag) const;
+
+  // Gets the value of a tag of byte vector type.
+  // Returns false if the tag is not part of the directory or if the
+  // type is not BYTE or UNDEFINED.
+  bool Get(const Tag tag, std::vector<std::uint8_t>* value) const;
+
+  // Gets the value of a tag of type "ASCII".
+  // Returns false if the tag is not part of the directory or if its
+  // type is not ASCII.
+  // If *err is not equal to ERR_OK initially, this method does nothing.
+  bool Get(const Tag tag, std::string* value) const;
+
+  // Gets the value of a tag of type "SHORT" or "LONG".
+  // Returns false
+  // - if the tag is not part of the directory or
+  // - if the type is not SHORT or LONG, or
+  // - if, for the non-vector version, the number of elements is unequal to 1.
+  bool Get(const Tag tag, std::uint32_t* value) const;
+  bool Get(const Tag tag, std::vector<std::uint32_t>* value) const;
+
+  // Gets the value of a tag of type "SHORT", "LONG" or "RATIONAL".
+  // Returns false
+  // - if the tag is not part of the directory or
+  // - if the type is not SHORT, LONG or RATIONAL, or
+  // - if, for the non-vector version, the number of elements is unequal to 1.
+  bool Get(const Tag tag, Rational* value) const;
+  bool Get(const Tag tag, std::vector<Rational>* value) const;
+
+  // Gets the value of a tag of type "SSHORT", "SLONG" or "SRATIONAL".
+  // Returns false
+  // - if the tag is not part of the directory or
+  // - if the type is not SSHORT, SLONG or SRATIONAL, or
+  // - if, for the non-vector version, the number of elements is unequal to 1.
+  bool Get(const Tag tag, SRational* value) const;
+  bool Get(const Tag tag, std::vector<SRational>* value) const;
+
+  // Gets the 'offset' to the value data in the file and its 'length' in bytes.
+  // Returns false if the 'tag' is not part of the directory or if its type does
+  // not match the desired 'type'.
+  bool GetOffsetAndLength(const Tag tag, const Type type, std::uint32_t* offset,
+                          std::uint32_t* length) const;
+
+  // Adds a tag to the directory, setting its type, number of elements
+  // ('count'), the offset to the binary data in the file ('offset') and the
+  // associated binary data ('value'). The binary data is encoded according to
+  // the TIFF specification with the endianness that was specified when this
+  // object was constructed. The caller must ensure that the size of 'value' and
+  // the data it contains are consistent with 'type' and 'count'. It is not
+  // legal to call this method with a tag that is already contained in the
+  // directory.
+  void AddEntry(const Tag tag, const Type type, const std::uint32_t count,
+                const std::uint32_t offset,
+                const std::vector<std::uint8_t>& value);
+
+  // Add a subdirectory to the directory.
+  void AddSubDirectory(const TiffDirectory& sub_directory);
+
+  // Returns a vector of all subdirectories contained in this directory.
+  const std::vector<TiffDirectory>& GetSubDirectories() const;
+
+ private:
+  struct DirectoryEntry {
+    Type type;
+    std::uint32_t count;   // The number of values of type, not a byte count.
+    std::uint32_t offset;  // Offset of the entry's data in the file. '0' means
+                           // the offset is not set.
+    std::vector<std::uint8_t> value;
+  };
+
+  const DirectoryEntry* Find(const Tag tag) const;
+
+  std::map<Tag, DirectoryEntry> directory_entries_;
+  std::vector<Tag> tag_order_;
+  std::vector<TiffDirectory> sub_directories_;
+  Endian endian_;
+};
+
+// Returns the number of bytes a single value of 'type' requires; this is
+// guaranteed to be in the range of 0 to 8.
+// Returns 0 if 'type' is TIFF_TYPE_NONE or invalid. Sets 'success' to false if
+// 'type' is invalid. If you are not interested in 'success' you can set it to
+// a nullptr.
+size_t SizeOfType(const TiffDirectory::Type type, bool* success);
+
+}  // namespace tiff_directory
+}  // namespace piex
+
+#endif  // PIEX_TIFF_DIRECTORY_TIFF_DIRECTORY_H_