The Tor Browser: gfx/ots/include/opentype-sanitiser.h@b8a032363ba2 (annotated)

gfx/ots/include/opentype-sanitiser.h@b8a032363ba2 (annotated)

gfx/ots/include/opentype-sanitiser.h

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 // Copyright (c) 2009 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 OPENTYPE_SANITISER_H_
 #define OPENTYPE_SANITISER_H_
 #if defined(_WIN32) || defined(__CYGWIN__)
   #define OTS_DLL_IMPORT __declspec(dllimport)
   #define OTS_DLL_EXPORT __declspec(dllexport)
 #else
   #if __GNUC__ >= 4
     #define OTS_DLL_IMPORT __attribute__((visibility ("default")))
     #define OTS_DLL_EXPORT __attribute__((visibility ("default")))
   #endif
 #endif
 #ifdef OTS_DLL
   #ifdef OTS_DLL_EXPORTS
     #define OTS_API OTS_DLL_EXPORT
   #else
     #define OTS_API OTS_DLL_IMPORT
   #endif
 #else
   #define OTS_API
 #endif
 #if defined(_WIN32)
 #include <stdlib.h>
 typedef signed char int8_t;
 typedef unsigned char uint8_t;
 typedef short int16_t;
 typedef unsigned short uint16_t;
 typedef int int32_t;
 typedef unsigned int uint32_t;
 typedef __int64 int64_t;
 typedef unsigned __int64 uint64_t;
 #define ntohl(x) _byteswap_ulong (x)
 #define ntohs(x) _byteswap_ushort (x)
 #define htonl(x) _byteswap_ulong (x)
 #define htons(x) _byteswap_ushort (x)
 #else
 #include <arpa/inet.h>
 #include <stdint.h>
 #endif
 #include <algorithm>
 #include <cassert>
 #include <cstddef>
 #include <cstring>
 namespace ots {
 // -----------------------------------------------------------------------------
 // This is an interface for an abstract stream class which is used for writing
 // the serialised results out.
 // -----------------------------------------------------------------------------
 class OTSStream {
  public:
   OTSStream() {
     ResetChecksum();
   }
   virtual ~OTSStream() {}
   // This should be implemented to perform the actual write.
   virtual bool WriteRaw(const void *data, size_t length) = 0;
   bool Write(const void *data, size_t length) {
     if (!length) return false;
     const size_t orig_length = length;
     size_t offset = 0;
     if (chksum_buffer_offset_) {
       const size_t l =
         std::min(length, static_cast<size_t>(4) - chksum_buffer_offset_);
       std::memcpy(chksum_buffer_ + chksum_buffer_offset_, data, l);
       chksum_buffer_offset_ += l;
       offset += l;
       length -= l;
     }
     if (chksum_buffer_offset_ == 4) {
       uint32_t tmp;
       std::memcpy(&tmp, chksum_buffer_, 4);
       chksum_ += ntohl(tmp);
       chksum_buffer_offset_ = 0;
     }
     while (length >= 4) {
       uint32_t tmp;
       std::memcpy(&tmp, reinterpret_cast<const uint8_t *>(data) + offset,
         sizeof(uint32_t));
       chksum_ += ntohl(tmp);
       length -= 4;
       offset += 4;
     }
     if (length) {
       if (chksum_buffer_offset_ != 0) return false;  // not reached
       if (length > 4) return false;  // not reached
       std::memcpy(chksum_buffer_,
              reinterpret_cast<const uint8_t*>(data) + offset, length);
       chksum_buffer_offset_ = length;
     }
     return WriteRaw(data, orig_length);
   }
   virtual bool Seek(off_t position) = 0;
   virtual off_t Tell() const = 0;
   virtual bool Pad(size_t bytes) {
     static const uint32_t kZero = 0;
     while (bytes >= 4) {
       if (!WriteTag(kZero)) return false;
       bytes -= 4;
     }
     while (bytes) {
       static const uint8_t kZerob = 0;
       if (!Write(&kZerob, 1)) return false;
       bytes--;
     }
     return true;
   }
   bool WriteU8(uint8_t v) {
     return Write(&v, sizeof(v));
   }
   bool WriteU16(uint16_t v) {
     v = htons(v);
     return Write(&v, sizeof(v));
   }
   bool WriteS16(int16_t v) {
     v = htons(v);
     return Write(&v, sizeof(v));
   }
   bool WriteU24(uint32_t v) {
     v = htonl(v);
     return Write(reinterpret_cast<uint8_t*>(&v)+1, 3);
   }
   bool WriteU32(uint32_t v) {
     v = htonl(v);
     return Write(&v, sizeof(v));
   }
   bool WriteS32(int32_t v) {
     v = htonl(v);
     return Write(&v, sizeof(v));
   }
   bool WriteR64(uint64_t v) {
     return Write(&v, sizeof(v));
   }
   bool WriteTag(uint32_t v) {
     return Write(&v, sizeof(v));
   }
   void ResetChecksum() {
     chksum_ = 0;
     chksum_buffer_offset_ = 0;
   }
   uint32_t chksum() const {
     assert(chksum_buffer_offset_ == 0);
     return chksum_;
   }
   struct ChecksumState {
     uint32_t chksum;
     uint8_t chksum_buffer[4];
     unsigned chksum_buffer_offset;
   };
   ChecksumState SaveChecksumState() const {
     ChecksumState s;
     s.chksum = chksum_;
     s.chksum_buffer_offset = chksum_buffer_offset_;
     std::memcpy(s.chksum_buffer, chksum_buffer_, 4);
     return s;
   }
   void RestoreChecksum(const ChecksumState &s) {
     assert(chksum_buffer_offset_ == 0);
     chksum_ += s.chksum;
     chksum_buffer_offset_ = s.chksum_buffer_offset;
     std::memcpy(chksum_buffer_, s.chksum_buffer, 4);
   }
  protected:
   uint32_t chksum_;
   uint8_t chksum_buffer_[4];
   unsigned chksum_buffer_offset_;
 };
 // -----------------------------------------------------------------------------
 // Process a given OpenType file and write out a sanitised version
 //   output: a pointer to an object implementing the OTSStream interface. The
 //     sanitisied output will be written to this. In the even of a failure,
 //     partial output may have been written.
 //   input: the OpenType file
 //   length: the size, in bytes, of |input|
 // -----------------------------------------------------------------------------
 bool OTS_API Process(OTSStream *output, const uint8_t *input, size_t length);
 // Signature of the function to be provided by the client in order to report errors.
 // The return type is a boolean so that it can be used within an expression,
 // but the actual value is ignored. (Suggested convention is to always return 'false'.)
 #ifdef __GCC__
 #define MSGFUNC_FMT_ATTR __attribute__((format(printf, 2, 3)))
 #else
 #define MSGFUNC_FMT_ATTR
 #endif
 typedef bool (*MessageFunc)(void *user_data, const char *format, ...)  MSGFUNC_FMT_ATTR;
 // Set a callback function that will be called when OTS is reporting an error.
 void OTS_API SetMessageCallback(MessageFunc func, void *user_data);
 enum TableAction {
   TABLE_ACTION_DEFAULT,  // Use OTS's default action for that table
   TABLE_ACTION_SANITIZE, // Sanitize the table, potentially droping it
   TABLE_ACTION_PASSTHRU, // Serialize the table unchanged
   TABLE_ACTION_DROP      // Drop the table
 };
 // Signature of the function to be provided by the client to decide what action
 // to do for a given table.
 typedef TableAction (*TableActionFunc)(uint32_t tag, void *user_data);
 // Set a callback function that will be called when OTS needs to decide what to
 // do for a font table.
 void OTS_API SetTableActionCallback(TableActionFunc func, void *user_data);
 // Force to disable debug output even when the library is compiled with
 // -DOTS_DEBUG.
 void DisableDebugOutput();
 #ifdef MOZ_OTS_WOFF2
 // Enable WOFF2 support(experimental).
 void EnableWOFF2();
 #endif
 }  // namespace ots
 #endif  // OPENTYPE_SANITISER_H_

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gfx/ots/include/opentype-sanitiser.h@b8a032363ba2 (annotated)

gfx/ots/include/opentype-sanitiser.h