diff options
Diffstat (limited to 'core/fxcodec/lgif/cfx_lzwdecoder.cpp')
| -rw-r--r-- | core/fxcodec/lgif/cfx_lzwdecoder.cpp | 184 |
1 files changed, 0 insertions, 184 deletions
diff --git a/core/fxcodec/lgif/cfx_lzwdecoder.cpp b/core/fxcodec/lgif/cfx_lzwdecoder.cpp deleted file mode 100644 index 9479eeafaa..0000000000 --- a/core/fxcodec/lgif/cfx_lzwdecoder.cpp +++ /dev/null @@ -1,184 +0,0 @@ -// Copyright 2017 PDFium Authors. All rights reserved. -// Use of this source code is governed by a BSD-style license that can be -// found in the LICENSE file. - -// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com - -#include "core/fxcodec/lgif/cfx_lzwdecoder.h" - -#include <algorithm> -#include <memory> -#include <utility> - -#include "core/fxcodec/lbmp/fx_bmp.h" -#include "third_party/base/numerics/safe_math.h" -#include "third_party/base/ptr_util.h" -#include "third_party/base/stl_util.h" - -std::unique_ptr<CFX_LZWDecoder> CFX_LZWDecoder::Create(uint8_t color_exp, - uint8_t code_exp) { - if (code_exp > GIF_MAX_LZW_EXP || code_exp + 1 < color_exp) - return nullptr; - return std::unique_ptr<CFX_LZWDecoder>( - new CFX_LZWDecoder(color_exp, code_exp)); -} - -CFX_LZWDecoder::CFX_LZWDecoder(uint8_t color_exp, uint8_t code_exp) - : code_size_(code_exp), - code_size_cur_(0), - code_color_end_(static_cast<uint16_t>(2 << color_exp)), - code_clear_(static_cast<uint16_t>(1 << code_exp)), - code_end_(static_cast<uint16_t>((1 << code_exp) + 1)), - code_next_(0), - code_first_(0), - stack_size_(0), - code_old_(0), - next_in_(nullptr), - avail_in_(0), - bits_left_(0), - code_store_(0) {} - -CFX_LZWDecoder::~CFX_LZWDecoder() {} - -GifDecodeStatus CFX_LZWDecoder::Decode(uint8_t* src_buf, - uint32_t src_size, - uint8_t* des_buf, - uint32_t* des_size) { - if (!src_buf || src_size == 0 || !des_buf || !des_size) - return GifDecodeStatus::Error; - - if (*des_size == 0) - return GifDecodeStatus::InsufficientDestSize; - - next_in_ = src_buf; - avail_in_ = src_size; - - ClearTable(); - - uint32_t i = 0; - if (stack_size_ != 0) { - if (*des_size < stack_size_) { - memcpy(des_buf, &stack_[GIF_MAX_LZW_CODE - stack_size_], *des_size); - stack_size_ -= static_cast<uint16_t>(*des_size); - return GifDecodeStatus::InsufficientDestSize; - } - - memcpy(des_buf, &stack_[GIF_MAX_LZW_CODE - stack_size_], stack_size_); - des_buf += stack_size_; - i += stack_size_; - stack_size_ = 0; - } - - while (i <= *des_size && (avail_in_ > 0 || bits_left_ >= code_size_cur_)) { - if (code_size_cur_ > GIF_MAX_LZW_EXP) - return GifDecodeStatus::Error; - - if (avail_in_ > 0) { - if (bits_left_ > 31) - return GifDecodeStatus::Error; - - pdfium::base::CheckedNumeric<uint32_t> safe_code = *next_in_++; - safe_code <<= bits_left_; - safe_code |= code_store_; - if (!safe_code.IsValid()) - return GifDecodeStatus::Error; - - code_store_ = safe_code.ValueOrDie(); - --avail_in_; - bits_left_ += 8; - } - - while (bits_left_ >= code_size_cur_) { - uint16_t code = - static_cast<uint16_t>(code_store_) & ((1 << code_size_cur_) - 1); - code_store_ >>= code_size_cur_; - bits_left_ -= code_size_cur_; - if (code == code_clear_) { - ClearTable(); - continue; - } - if (code == code_end_) { - *des_size = i; - return GifDecodeStatus::Success; - } - - if (code_old_ != static_cast<uint16_t>(-1)) { - if (code_next_ < GIF_MAX_LZW_CODE) { - if (code == code_next_) { - AddCode(code_old_, code_first_); - if (!DecodeString(code)) - return GifDecodeStatus::Error; - } else if (code > code_next_) { - return GifDecodeStatus::Error; - } else { - if (!DecodeString(code)) - return GifDecodeStatus::Error; - - uint8_t append_char = stack_[GIF_MAX_LZW_CODE - stack_size_]; - AddCode(code_old_, append_char); - } - } - } else { - if (!DecodeString(code)) - return GifDecodeStatus::Error; - } - - code_old_ = code; - if (i + stack_size_ > *des_size) { - memcpy(des_buf, &stack_[GIF_MAX_LZW_CODE - stack_size_], *des_size - i); - stack_size_ -= static_cast<uint16_t>(*des_size - i); - return GifDecodeStatus::InsufficientDestSize; - } - - memcpy(des_buf, &stack_[GIF_MAX_LZW_CODE - stack_size_], stack_size_); - des_buf += stack_size_; - i += stack_size_; - stack_size_ = 0; - } - } - - if (avail_in_ != 0) - return GifDecodeStatus::Error; - - *des_size = i; - return GifDecodeStatus::Unfinished; -} - -void CFX_LZWDecoder::ClearTable() { - code_size_cur_ = code_size_ + 1; - code_next_ = code_end_ + 1; - code_old_ = static_cast<uint16_t>(-1); - memset(code_table_, 0, sizeof(code_table_)); - memset(stack_, 0, sizeof(stack_)); - for (uint16_t i = 0; i < code_clear_; i++) - code_table_[i].suffix = static_cast<uint8_t>(i); -} - -void CFX_LZWDecoder::AddCode(uint16_t prefix_code, uint8_t append_char) { - if (code_next_ == GIF_MAX_LZW_CODE) - return; - - code_table_[code_next_].prefix = prefix_code; - code_table_[code_next_].suffix = append_char; - if (++code_next_ < GIF_MAX_LZW_CODE) { - if (code_next_ >> code_size_cur_) - code_size_cur_++; - } -} - -bool CFX_LZWDecoder::DecodeString(uint16_t code) { - stack_size_ = 0; - while (code >= code_clear_ && code <= code_next_) { - if (code == code_table_[code].prefix || stack_size_ == GIF_MAX_LZW_CODE - 1) - return false; - - stack_[GIF_MAX_LZW_CODE - 1 - stack_size_++] = code_table_[code].suffix; - code = code_table_[code].prefix; - } - if (code >= code_color_end_) - return false; - - stack_[GIF_MAX_LZW_CODE - 1 - stack_size_++] = static_cast<uint8_t>(code); - code_first_ = static_cast<uint8_t>(code); - return true; -} |