BaseTools/Source/C/LzmaCompress/Sdk/C/7zStream.c

   1 /* 7zStream.c -- 7z Stream functions
   2 2013-11-12 : Igor Pavlov : Public domain */
   3
   4 #include "Precomp.h"
   5
   6 #include <string.h>
   7
   8 #include "7zTypes.h"
   9
  10 SRes SeqInStream_Read2(ISeqInStream *stream, void *buf, size_t size, SRes errorType)
  11 {
  12   while (size != 0)
  13   {
  14     size_t processed = size;
  15     RINOK(stream->Read(stream, buf, &processed));
  16     if (processed == 0)
  17       return errorType;
  18     buf = (void *)((Byte *)buf + processed);
  19     size -= processed;
  20   }
  21   return SZ_OK;
  22 }
  23
  24 SRes SeqInStream_Read(ISeqInStream *stream, void *buf, size_t size)
  25 {
  26   return SeqInStream_Read2(stream, buf, size, SZ_ERROR_INPUT_EOF);
  27 }
  28
  29 SRes SeqInStream_ReadByte(ISeqInStream *stream, Byte *buf)
  30 {
  31   size_t processed = 1;
  32   RINOK(stream->Read(stream, buf, &processed));
  33   return (processed == 1) ? SZ_OK : SZ_ERROR_INPUT_EOF;
  34 }
  35
  36 SRes LookInStream_SeekTo(ILookInStream *stream, UInt64 offset)
  37 {
  38   Int64 t = offset;
  39   return stream->Seek(stream, &t, SZ_SEEK_SET);
  40 }
  41
  42 SRes LookInStream_LookRead(ILookInStream *stream, void *buf, size_t *size)
  43 {
  44   const void *lookBuf;
  45   if (*size == 0)
  46     return SZ_OK;
  47   RINOK(stream->Look(stream, &lookBuf, size));
  48   memcpy(buf, lookBuf, *size);
  49   return stream->Skip(stream, *size);
  50 }
  51
  52 SRes LookInStream_Read2(ILookInStream *stream, void *buf, size_t size, SRes errorType)
  53 {
  54   while (size != 0)
  55   {
  56     size_t processed = size;
  57     RINOK(stream->Read(stream, buf, &processed));
  58     if (processed == 0)
  59       return errorType;
  60     buf = (void *)((Byte *)buf + processed);
  61     size -= processed;
  62   }
  63   return SZ_OK;
  64 }
  65
  66 SRes LookInStream_Read(ILookInStream *stream, void *buf, size_t size)
  67 {
  68   return LookInStream_Read2(stream, buf, size, SZ_ERROR_INPUT_EOF);
  69 }
  70
  71 static SRes LookToRead_Look_Lookahead(void *pp, const void **buf, size_t *size)
  72 {
  73   SRes res = SZ_OK;
  74   CLookToRead *p = (CLookToRead *)pp;
  75   size_t size2 = p->size - p->pos;
  76   if (size2 == 0 && *size > 0)
  77   {
  78     p->pos = 0;
  79     size2 = LookToRead_BUF_SIZE;
  80     res = p->realStream->Read(p->realStream, p->buf, &size2);
  81     p->size = size2;
  82   }
  83   if (size2 < *size)
  84     *size = size2;
  85   *buf = p->buf + p->pos;
  86   return res;
  87 }
  88
  89 static SRes LookToRead_Look_Exact(void *pp, const void **buf, size_t *size)
  90 {
  91   SRes res = SZ_OK;
  92   CLookToRead *p = (CLookToRead *)pp;
  93   size_t size2 = p->size - p->pos;
  94   if (size2 == 0 && *size > 0)
  95   {
  96     p->pos = 0;
  97     if (*size > LookToRead_BUF_SIZE)
  98       *size = LookToRead_BUF_SIZE;
  99     res = p->realStream->Read(p->realStream, p->buf, size);
 100     size2 = p->size = *size;
 101   }
 102   if (size2 < *size)
 103     *size = size2;
 104   *buf = p->buf + p->pos;
 105   return res;
 106 }
 107
 108 static SRes LookToRead_Skip(void *pp, size_t offset)
 109 {
 110   CLookToRead *p = (CLookToRead *)pp;
 111   p->pos += offset;
 112   return SZ_OK;
 113 }
 114
 115 static SRes LookToRead_Read(void *pp, void *buf, size_t *size)
 116 {
 117   CLookToRead *p = (CLookToRead *)pp;
 118   size_t rem = p->size - p->pos;
 119   if (rem == 0)
 120     return p->realStream->Read(p->realStream, buf, size);
 121   if (rem > *size)
 122     rem = *size;
 123   memcpy(buf, p->buf + p->pos, rem);
 124   p->pos += rem;
 125   *size = rem;
 126   return SZ_OK;
 127 }
 128
 129 static SRes LookToRead_Seek(void *pp, Int64 *pos, ESzSeek origin)
 130 {
 131   CLookToRead *p = (CLookToRead *)pp;
 132   p->pos = p->size = 0;
 133   return p->realStream->Seek(p->realStream, pos, origin);
 134 }
 135
 136 void LookToRead_CreateVTable(CLookToRead *p, int lookahead)
 137 {
 138   p->s.Look = lookahead ?
 139       LookToRead_Look_Lookahead :
 140       LookToRead_Look_Exact;
 141   p->s.Skip = LookToRead_Skip;
 142   p->s.Read = LookToRead_Read;
 143   p->s.Seek = LookToRead_Seek;
 144 }
 145
 146 void LookToRead_Init(CLookToRead *p)
 147 {
 148   p->pos = p->size = 0;
 149 }
 150
 151 static SRes SecToLook_Read(void *pp, void *buf, size_t *size)
 152 {
 153   CSecToLook *p = (CSecToLook *)pp;
 154   return LookInStream_LookRead(p->realStream, buf, size);
 155 }
 156
 157 void SecToLook_CreateVTable(CSecToLook *p)
 158 {
 159   p->s.Read = SecToLook_Read;
 160 }
 161
 162 static SRes SecToRead_Read(void *pp, void *buf, size_t *size)
 163 {
 164   CSecToRead *p = (CSecToRead *)pp;
 165   return p->realStream->Read(p->realStream, buf, size);
 166 }
 167
 168 void SecToRead_CreateVTable(CSecToRead *p)
 169 {
 170   p->s.Read = SecToRead_Read;
 171 }