Remove unused PS generation code.

core/fxcodec/codec/fx_codec_flate.cpp

 // Copyright 2014 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/codec/codec_int.h"
 
 #include <algorithm>
 #include <memory>
@@ skipping 11 matching lines @@
 }
 static void my_free_func(void* opaque, void* address) {
   FX_Free(address);
 }
 static int FPDFAPI_FlateGetTotalOut(void* context) {
   return ((z_stream*)context)->total_out;
 }
 static int FPDFAPI_FlateGetTotalIn(void* context) {
   return ((z_stream*)context)->total_in;
 }
-static void FPDFAPI_FlateCompress(unsigned char* dest_buf,
+
+static bool FPDFAPI_FlateCompress(unsigned char* dest_buf,
                                   unsigned long* dest_size,
                                   const unsigned char* src_buf,
                                   unsigned long src_size) {
-  compress(dest_buf, dest_size, src_buf, src_size);
+  return compress(dest_buf, dest_size, src_buf, src_size) == Z_OK;
 }
+
 void* FPDFAPI_FlateInit(void* (*alloc_func)(void*, unsigned int, unsigned int),
                         void (*free_func)(void*, void*)) {
   z_stream* p = (z_stream*)alloc_func(0, 1, sizeof(z_stream));
-  if (!p) {
-    return NULL;
-  }
+  if (!p)
+    return nullptr;
+
   FXSYS_memset(p, 0, sizeof(z_stream));
   p->zalloc = alloc_func;
   p->zfree = free_func;
   inflateInit(p);
   return p;
 }
+
 void FPDFAPI_FlateInput(void* context,
                         const unsigned char* src_buf,
                         unsigned int src_size) {
   ((z_stream*)context)->next_in = (unsigned char*)src_buf;
   ((z_stream*)context)->avail_in = src_size;
 }
+
 int FPDFAPI_FlateOutput(void* context,
                         unsigned char* dest_buf,
                         unsigned int dest_size) {
   ((z_stream*)context)->next_out = dest_buf;
   ((z_stream*)context)->avail_out = dest_size;
   unsigned int pre_pos = (unsigned int)FPDFAPI_FlateGetTotalOut(context);
   int ret = inflate((z_stream*)context, Z_SYNC_FLUSH);
   unsigned int post_pos = (unsigned int)FPDFAPI_FlateGetTotalOut(context);
   unsigned int written = post_pos - pre_pos;
   if (written < dest_size) {
     FXSYS_memset(dest_buf + written, '\0', dest_size - written);
   }
   return ret;
 }
+
 int FPDFAPI_FlateGetAvailIn(void* context) {
   return ((z_stream*)context)->avail_in;
 }
+
 int FPDFAPI_FlateGetAvailOut(void* context) {
   return ((z_stream*)context)->avail_out;
 }
+
 void FPDFAPI_FlateEnd(void* context) {
   inflateEnd((z_stream*)context);
   ((z_stream*)context)->zfree(0, context);
 }
+
 }  // extern "C"
 
 namespace {
 
 class CLZWDecoder {
  public:
   int Decode(uint8_t* output,
              uint32_t& outlen,
              const uint8_t* input,
              uint32_t& size,
              FX_BOOL bEarlyChange);
 
  private:
   void AddCode(uint32_t prefix_code, uint8_t append_char);
   void DecodeString(uint32_t code);
 
   uint32_t m_InPos;
   uint32_t m_OutPos;
   uint8_t* m_pOutput;
   const uint8_t* m_pInput;
   FX_BOOL m_Early;
   uint32_t m_CodeArray[5021];
   uint32_t m_nCodes;
   uint8_t m_DecodeStack[4000];
   uint32_t m_StackLen;
   int m_CodeLen;
 };
+
 void CLZWDecoder::AddCode(uint32_t prefix_code, uint8_t append_char) {
   if (m_nCodes + m_Early == 4094) {
     return;
   }
   m_CodeArray[m_nCodes++] = (prefix_code << 16) | append_char;
   if (m_nCodes + m_Early == 512 - 258) {
     m_CodeLen = 10;
   } else if (m_nCodes + m_Early == 1024 - 258) {
     m_CodeLen = 11;
   } else if (m_nCodes + m_Early == 2048 - 258) {
@@ skipping 105 matching lines @@
         AddCode(old_code, last_char);
       }
       old_code = code;
     }
   }
   dest_size = m_OutPos;
   src_size = (m_InPos + 7) / 8;
   return 0;
 }
 
-uint8_t PaethPredictor(int a, int b, int c) {
+uint8_t PathPredictor(int a, int b, int c) {
   int p = a + b - c;
   int pa = FXSYS_abs(p - a);
   int pb = FXSYS_abs(p - b);
   int pc = FXSYS_abs(p - c);
-  if (pa <= pb && pa <= pc) {
+  if (pa <= pb && pa <= pc)
     return (uint8_t)a;
-  }
-  if (pb <= pc) {
+  if (pb <= pc)
     return (uint8_t)b;
-  }
   return (uint8_t)c;
 }
 
-FX_BOOL PNG_PredictorEncode(uint8_t*& data_buf,
-                            uint32_t& data_size,
-                            int predictor,
-                            int Colors,
-                            int BitsPerComponent,
-                            int Columns) {
-  const int BytesPerPixel = (Colors * BitsPerComponent + 7) / 8;
-  const int row_size = (Colors * BitsPerComponent * Columns + 7) / 8;
-  if (row_size <= 0)
-    return FALSE;
-  const int row_count = (data_size + row_size - 1) / row_size;
-  const int last_row_size = data_size % row_size;
+void PNG_PredictorEncode(uint8_t** data_buf, uint32_t* data_size) {
+  const int row_size = 7;
+  const int row_count = (*data_size + row_size - 1) / row_size;
+  const int last_row_size = *data_size % row_size;
   uint8_t* dest_buf = FX_Alloc2D(uint8_t, row_size + 1, row_count);
   int byte_cnt = 0;
-  uint8_t* pSrcData = data_buf;
+  uint8_t* pSrcData = *data_buf;
   uint8_t* pDestData = dest_buf;
   for (int row = 0; row < row_count; row++) {
-    if (predictor == 10) {
-      pDestData[0] = 0;
-      int move_size = row_size;
-      if (move_size * (row + 1) > (int)data_size) {
-        move_size = data_size - (move_size * row);
-      }
-      FXSYS_memmove(pDestData + 1, pSrcData, move_size);
-      pDestData += (move_size + 1);
-      pSrcData += move_size;
-      byte_cnt += move_size;
-      continue;
-    }
-    for (int byte = 0; byte < row_size && byte_cnt < (int)data_size; byte++) {
-      switch (predictor) {
-        case 11: {
-          pDestData[0] = 1;
-          uint8_t left = 0;
-          if (byte >= BytesPerPixel) {
-            left = pSrcData[byte - BytesPerPixel];
-          }
-          pDestData[byte + 1] = pSrcData[byte] - left;
-        } break;
-        case 12: {
-          pDestData[0] = 2;
-          uint8_t up = 0;
-          if (row) {
-            up = pSrcData[byte - row_size];
-          }
-          pDestData[byte + 1] = pSrcData[byte] - up;
-        } break;
-        case 13: {
-          pDestData[0] = 3;
-          uint8_t left = 0;
-          if (byte >= BytesPerPixel) {
-            left = pSrcData[byte - BytesPerPixel];
-          }
-          uint8_t up = 0;
-          if (row) {
-            up = pSrcData[byte - row_size];
-          }
-          pDestData[byte + 1] = pSrcData[byte] - (left + up) / 2;
-        } break;
-        case 14: {
-          pDestData[0] = 4;
-          uint8_t left = 0;
-          if (byte >= BytesPerPixel) {
-            left = pSrcData[byte - BytesPerPixel];
-          }
-          uint8_t up = 0;
-          if (row) {
-            up = pSrcData[byte - row_size];
-          }
-          uint8_t upper_left = 0;
-          if (byte >= BytesPerPixel && row) {
-            upper_left = pSrcData[byte - row_size - BytesPerPixel];
-          }
-          pDestData[byte + 1] =
-              pSrcData[byte] - PaethPredictor(left, up, upper_left);
-        } break;
-        default: { pDestData[byte + 1] = pSrcData[byte]; } break;
-      }
-      byte_cnt++;
+    for (int byte = 0; byte < row_size && byte_cnt < (int)*data_size; byte++) {
+      pDestData[0] = 2;
+      uint8_t up = 0;
+      if (row)
+        up = pSrcData[byte - row_size];
+      pDestData[byte + 1] = pSrcData[byte] - up;
+      ++byte_cnt;
     }
     pDestData += (row_size + 1);
     pSrcData += row_size;
   }
-  FX_Free(data_buf);
-  data_buf = dest_buf;
-  data_size = (row_size + 1) * row_count -
-              (last_row_size > 0 ? (row_size - last_row_size) : 0);
-  return TRUE;
+  FX_Free(*data_buf);
+  *data_buf = dest_buf;
+  *data_size = (row_size + 1) * row_count -
+               (last_row_size > 0 ? (row_size - last_row_size) : 0);
 }
 
 void PNG_PredictLine(uint8_t* pDestData,
                      const uint8_t* pSrcData,
                      const uint8_t* pLastLine,
                      int bpc,
                      int nColors,
                      int nPixels) {
   int row_size = (nPixels * bpc * nColors + 7) / 8;
   int BytesPerPixel = (bpc * nColors + 7) / 8;
@@ skipping 39 matching lines @@
           left = pDestData[byte - BytesPerPixel];
         }
         uint8_t up = 0;
         if (pLastLine) {
           up = pLastLine[byte];
         }
         uint8_t upper_left = 0;
         if (byte >= BytesPerPixel && pLastLine) {
           upper_left = pLastLine[byte - BytesPerPixel];
         }
-        pDestData[byte] = raw_byte + PaethPredictor(left, up, upper_left);
+        pDestData[byte] = raw_byte + PathPredictor(left, up, upper_left);
         break;
       }
       default:
         pDestData[byte] = raw_byte;
         break;
     }
   }
 }
 
 FX_BOOL PNG_Predictor(uint8_t*& data_buf,
@@ skipping 64 matching lines @@
             left = pDestData[byte - BytesPerPixel];
           }
           uint8_t up = 0;
           if (row) {
             up = pDestData[byte - row_size];
           }
           uint8_t upper_left = 0;
           if (byte >= BytesPerPixel && row) {
             upper_left = pDestData[byte - row_size - BytesPerPixel];
           }
-          pDestData[byte] = raw_byte + PaethPredictor(left, up, upper_left);
+          pDestData[byte] = raw_byte + PathPredictor(left, up, upper_left);
           break;
         }
         default:
           pDestData[byte] = raw_byte;
           break;
       }
       byte_cnt++;
     }
     pSrcData += row_size + 1;
     pDestData += row_size;
   }
   FX_Free(data_buf);
   data_buf = dest_buf;
   data_size = row_size * row_count -
               (last_row_size > 0 ? (row_size + 1 - last_row_size) : 0);
   return TRUE;
 }
 
-void TIFF_PredictorEncodeLine(uint8_t* dest_buf,
-                              int row_size,
-                              int BitsPerComponent,
-                              int Colors,
-                              int Columns) {
-  int BytesPerPixel = BitsPerComponent * Colors / 8;
-  if (BitsPerComponent < 8) {
-    uint8_t mask = 0x01;
-    if (BitsPerComponent == 2) {
-      mask = 0x03;
-    } else if (BitsPerComponent == 4) {
-      mask = 0x0F;
-    }
-    int row_bits = Colors * BitsPerComponent * Columns;
-    for (int i = row_bits - BitsPerComponent; i >= BitsPerComponent;
-         i -= BitsPerComponent) {
-      int col = i % 8;
-      int index = i / 8;
-      int col_pre =
-          (col == 0) ? (8 - BitsPerComponent) : (col - BitsPerComponent);
-      int index_pre = (col == 0) ? (index - 1) : index;
-      uint8_t cur = (dest_buf[index] >> (8 - col - BitsPerComponent)) & mask;
-      uint8_t left =
-          (dest_buf[index_pre] >> (8 - col_pre - BitsPerComponent)) & mask;
-      cur -= left;
-      cur &= mask;
-      cur <<= (8 - col - BitsPerComponent);
-      dest_buf[index] &= ~(mask << ((8 - col - BitsPerComponent)));
-      dest_buf[index] |= cur;
-    }
-  } else if (BitsPerComponent == 8) {
-    for (int i = row_size - 1; i >= BytesPerPixel; i--) {
-      dest_buf[i] -= dest_buf[i - BytesPerPixel];
-    }
-  } else {
-    for (int i = row_size - BytesPerPixel; i >= BytesPerPixel;
-         i -= BytesPerPixel) {
-      uint16_t pixel = (dest_buf[i] << 8) | dest_buf[i + 1];
-      pixel -=
-          (dest_buf[i - BytesPerPixel] << 8) | dest_buf[i - BytesPerPixel + 1];
-      dest_buf[i] = pixel >> 8;
-      dest_buf[i + 1] = (uint8_t)pixel;
-    }
-  }
-}
-
-FX_BOOL TIFF_PredictorEncode(uint8_t*& data_buf,
-                             uint32_t& data_size,
-                             int Colors,
-                             int BitsPerComponent,
-                             int Columns) {
-  int row_size = (Colors * BitsPerComponent * Columns + 7) / 8;
-  if (row_size == 0)
-    return FALSE;
-  const int row_count = (data_size + row_size - 1) / row_size;
-  const int last_row_size = data_size % row_size;
-  for (int row = 0; row < row_count; row++) {
-    uint8_t* scan_line = data_buf + row * row_size;
-    if ((row + 1) * row_size > (int)data_size) {
-      row_size = last_row_size;
-    }
-    TIFF_PredictorEncodeLine(scan_line, row_size, BitsPerComponent, Colors,
-                             Columns);
-  }
-  return TRUE;
-}
-
 void TIFF_PredictLine(uint8_t* dest_buf,
                       uint32_t row_size,
                       int BitsPerComponent,
                       int Colors,
                       int Columns) {
   if (BitsPerComponent == 1) {
     int row_bits = std::min(BitsPerComponent * Colors * Columns,
                             pdfium::base::checked_cast<int>(row_size * 8));
     int index_pre = 0;
     int col_pre = 0;
@@ skipping 384 matching lines @@
   }
   FX_BOOL ret = TRUE;
   if (predictor_type == 2) {
     ret = PNG_Predictor(dest_buf, dest_size, Colors, BitsPerComponent, Columns);
   } else if (predictor_type == 1) {
     ret =
         TIFF_Predictor(dest_buf, dest_size, Colors, BitsPerComponent, Columns);
   }
   return ret ? offset : FX_INVALID_OFFSET;
 }
-FX_BOOL CCodec_FlateModule::Encode(const uint8_t* src_buf,
+
+bool CCodec_FlateModule::Encode(const uint8_t* src_buf,
+                                uint32_t src_size,
+                                uint8_t** dest_buf,
+                                uint32_t* dest_size) {
+  *dest_size = src_size + src_size / 1000 + 12;
+  *dest_buf = FX_Alloc(uint8_t, *dest_size);
+  unsigned long temp_size = *dest_size;
+  if (!FPDFAPI_FlateCompress(*dest_buf, &temp_size, src_buf, src_size))
+    return false;
+
+  *dest_size = (uint32_t)temp_size;
+  return true;
+}
+
+bool CCodec_FlateModule::PngEncode(const uint8_t* src_buf,
                                    uint32_t src_size,
-                                   int predictor,
-                                   int Colors,
-                                   int BitsPerComponent,
-                                   int Columns,
-                                   uint8_t*& dest_buf,
-                                   uint32_t& dest_size) {
-  if (predictor != 2 && predictor < 10) {
-    return Encode(src_buf, src_size, dest_buf, dest_size);
-  }
-  uint8_t* pSrcBuf = NULL;
-  pSrcBuf = FX_Alloc(uint8_t, src_size);
+                                   uint8_t** dest_buf,
+                                   uint32_t* dest_size) {
+  uint8_t* pSrcBuf = FX_Alloc(uint8_t, src_size);
   FXSYS_memcpy(pSrcBuf, src_buf, src_size);
-  FX_BOOL ret = TRUE;
-  if (predictor == 2) {
-    ret = TIFF_PredictorEncode(pSrcBuf, src_size, Colors, BitsPerComponent,
-                               Columns);
-  } else if (predictor >= 10) {
-    ret = PNG_PredictorEncode(pSrcBuf, src_size, predictor, Colors,
-                              BitsPerComponent, Columns);
-  }
-  if (ret)
-    ret = Encode(pSrcBuf, src_size, dest_buf, dest_size);
+  PNG_PredictorEncode(&pSrcBuf, &src_size);
+  bool ret = Encode(pSrcBuf, src_size, dest_buf, dest_size);
   FX_Free(pSrcBuf);
   return ret;
 }
-FX_BOOL CCodec_FlateModule::Encode(const uint8_t* src_buf,
-                                   uint32_t src_size,
-                                   uint8_t*& dest_buf,
-                                   uint32_t& dest_size) {
-  dest_size = src_size + src_size / 1000 + 12;
-  dest_buf = FX_Alloc(uint8_t, dest_size);
-  unsigned long temp_size = dest_size;
-  FPDFAPI_FlateCompress(dest_buf, &temp_size, src_buf, src_size);
-  dest_size = (uint32_t)temp_size;
-  return TRUE;
-}