1/* 7zStream.c -- 7z Stream functions
  22017-04-03 : Igor Pavlov : Public domain */
  3
  4#include "Precomp.h"
  5
  6#include <string.h>
  7
  8#include "7zTypes.h"
  9
 10SRes SeqInStream_Read2(const ISeqInStream *stream, void *buf, size_t size, SRes errorType)
 11{
 12  while (size != 0)
 13  {
 14    size_t processed = size;
 15    RINOK(ISeqInStream_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
 24SRes SeqInStream_Read(const ISeqInStream *stream, void *buf, size_t size)
 25{
 26  return SeqInStream_Read2(stream, buf, size, SZ_ERROR_INPUT_EOF);
 27}
 28
 29SRes SeqInStream_ReadByte(const ISeqInStream *stream, Byte *buf)
 30{
 31  size_t processed = 1;
 32  RINOK(ISeqInStream_Read(stream, buf, &processed));
 33  return (processed == 1) ? SZ_OK : SZ_ERROR_INPUT_EOF;
 34}
 35
 36
 37
 38SRes LookInStream_SeekTo(const ILookInStream *stream, UInt64 offset)
 39{
 40  Int64 t = offset;
 41  return ILookInStream_Seek(stream, &t, SZ_SEEK_SET);
 42}
 43
 44SRes LookInStream_LookRead(const ILookInStream *stream, void *buf, size_t *size)
 45{
 46  const void *lookBuf;
 47  if (*size == 0)
 48    return SZ_OK;
 49  RINOK(ILookInStream_Look(stream, &lookBuf, size));
 50  memcpy(buf, lookBuf, *size);
 51  return ILookInStream_Skip(stream, *size);
 52}
 53
 54SRes LookInStream_Read2(const ILookInStream *stream, void *buf, size_t size, SRes errorType)
 55{
 56  while (size != 0)
 57  {
 58    size_t processed = size;
 59    RINOK(ILookInStream_Read(stream, buf, &processed));
 60    if (processed == 0)
 61      return errorType;
 62    buf = (void *)((Byte *)buf + processed);
 63    size -= processed;
 64  }
 65  return SZ_OK;
 66}
 67
 68SRes LookInStream_Read(const ILookInStream *stream, void *buf, size_t size)
 69{
 70  return LookInStream_Read2(stream, buf, size, SZ_ERROR_INPUT_EOF);
 71}
 72
 73
 74
 75#define GET_LookToRead2 CLookToRead2 *p = CONTAINER_FROM_VTBL(pp, CLookToRead2, vt);
 76
 77static SRes LookToRead2_Look_Lookahead(const ILookInStream *pp, const void **buf, size_t *size)
 78{
 79  SRes res = SZ_OK;
 80  GET_LookToRead2
 81  size_t size2 = p->size - p->pos;
 82  if (size2 == 0 && *size != 0)
 83  {
 84    p->pos = 0;
 85    p->size = 0;
 86    size2 = p->bufSize;
 87    res = ISeekInStream_Read(p->realStream, p->buf, &size2);
 88    p->size = size2;
 89  }
 90  if (*size > size2)
 91    *size = size2;
 92  *buf = p->buf + p->pos;
 93  return res;
 94}
 95
 96static SRes LookToRead2_Look_Exact(const ILookInStream *pp, const void **buf, size_t *size)
 97{
 98  SRes res = SZ_OK;
 99  GET_LookToRead2
100  size_t size2 = p->size - p->pos;
101  if (size2 == 0 && *size != 0)
102  {
103    p->pos = 0;
104    p->size = 0;
105    if (*size > p->bufSize)
106      *size = p->bufSize;
107    res = ISeekInStream_Read(p->realStream, p->buf, size);
108    size2 = p->size = *size;
109  }
110  if (*size > size2)
111    *size = size2;
112  *buf = p->buf + p->pos;
113  return res;
114}
115
116static SRes LookToRead2_Skip(const ILookInStream *pp, size_t offset)
117{
118  GET_LookToRead2
119  p->pos += offset;
120  return SZ_OK;
121}
122
123static SRes LookToRead2_Read(const ILookInStream *pp, void *buf, size_t *size)
124{
125  GET_LookToRead2
126  size_t rem = p->size - p->pos;
127  if (rem == 0)
128    return ISeekInStream_Read(p->realStream, buf, size);
129  if (rem > *size)
130    rem = *size;
131  memcpy(buf, p->buf + p->pos, rem);
132  p->pos += rem;
133  *size = rem;
134  return SZ_OK;
135}
136
137static SRes LookToRead2_Seek(const ILookInStream *pp, Int64 *pos, ESzSeek origin)
138{
139  GET_LookToRead2
140  p->pos = p->size = 0;
141  return ISeekInStream_Seek(p->realStream, pos, origin);
142}
143
144void LookToRead2_CreateVTable(CLookToRead2 *p, int lookahead)
145{
146  p->vt.Look = lookahead ?
147      LookToRead2_Look_Lookahead :
148      LookToRead2_Look_Exact;
149  p->vt.Skip = LookToRead2_Skip;
150  p->vt.Read = LookToRead2_Read;
151  p->vt.Seek = LookToRead2_Seek;
152}
153
154
155
156static SRes SecToLook_Read(const ISeqInStream *pp, void *buf, size_t *size)
157{
158  CSecToLook *p = CONTAINER_FROM_VTBL(pp, CSecToLook, vt);
159  return LookInStream_LookRead(p->realStream, buf, size);
160}
161
162void SecToLook_CreateVTable(CSecToLook *p)
163{
164  p->vt.Read = SecToLook_Read;
165}
166
167static SRes SecToRead_Read(const ISeqInStream *pp, void *buf, size_t *size)
168{
169  CSecToRead *p = CONTAINER_FROM_VTBL(pp, CSecToRead, vt);
170  return ILookInStream_Read(p->realStream, buf, size);
171}
172
173void SecToRead_CreateVTable(CSecToRead *p)
174{
175  p->vt.Read = SecToRead_Read;
176}