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