1 /* 7zStream.c -- 7z Stream functions
2 2010-03-11 : Igor Pavlov : Public domain */
3 
4 #include <string.h>
5 
6 #include "Types.h"
7 
SeqInStream_Read2(ISeqInStream * stream,void * buf,size_t size,SRes errorType)8 SRes SeqInStream_Read2(ISeqInStream *stream, void *buf, size_t size, SRes errorType)
9 {
10   while (size != 0)
11   {
12     size_t processed = size;
13     RINOK(stream->Read(stream, buf, &processed));
14     if (processed == 0)
15       return errorType;
16     buf = (void *)((Byte *)buf + processed);
17     size -= processed;
18   }
19   return SZ_OK;
20 }
21 
SeqInStream_Read(ISeqInStream * stream,void * buf,size_t size)22 SRes SeqInStream_Read(ISeqInStream *stream, void *buf, size_t size)
23 {
24   return SeqInStream_Read2(stream, buf, size, SZ_ERROR_INPUT_EOF);
25 }
26 
SeqInStream_ReadByte(ISeqInStream * stream,Byte * buf)27 SRes SeqInStream_ReadByte(ISeqInStream *stream, Byte *buf)
28 {
29   size_t processed = 1;
30   RINOK(stream->Read(stream, buf, &processed));
31   return (processed == 1) ? SZ_OK : SZ_ERROR_INPUT_EOF;
32 }
33 
LookInStream_SeekTo(ILookInStream * stream,UInt64 offset)34 SRes LookInStream_SeekTo(ILookInStream *stream, UInt64 offset)
35 {
36   Int64 t = offset;
37   return stream->Seek(stream, &t, SZ_SEEK_SET);
38 }
39 
LookInStream_LookRead(ILookInStream * stream,void * buf,size_t * size)40 SRes LookInStream_LookRead(ILookInStream *stream, void *buf, size_t *size)
41 {
42   const void *lookBuf;
43   if (*size == 0)
44     return SZ_OK;
45   RINOK(stream->Look(stream, &lookBuf, size));
46   memcpy(buf, lookBuf, *size);
47   return stream->Skip(stream, *size);
48 }
49 
LookInStream_Read2(ILookInStream * stream,void * buf,size_t size,SRes errorType)50 SRes LookInStream_Read2(ILookInStream *stream, void *buf, size_t size, SRes errorType)
51 {
52   while (size != 0)
53   {
54     size_t processed = size;
55     RINOK(stream->Read(stream, buf, &processed));
56     if (processed == 0)
57       return errorType;
58     buf = (void *)((Byte *)buf + processed);
59     size -= processed;
60   }
61   return SZ_OK;
62 }
63 
LookInStream_Read(ILookInStream * stream,void * buf,size_t size)64 SRes LookInStream_Read(ILookInStream *stream, void *buf, size_t size)
65 {
66   return LookInStream_Read2(stream, buf, size, SZ_ERROR_INPUT_EOF);
67 }
68 
LookToRead_Look_Lookahead(void * pp,const void ** buf,size_t * size)69 static SRes LookToRead_Look_Lookahead(void *pp, const void **buf, size_t *size)
70 {
71   SRes res = SZ_OK;
72   CLookToRead *p = (CLookToRead *)pp;
73   size_t size2 = p->size - p->pos;
74   if (size2 == 0 && *size > 0)
75   {
76     p->pos = 0;
77     size2 = LookToRead_BUF_SIZE;
78     res = p->realStream->Read(p->realStream, p->buf, &size2);
79     p->size = size2;
80   }
81   if (size2 < *size)
82     *size = size2;
83   *buf = p->buf + p->pos;
84   return res;
85 }
86 
LookToRead_Look_Exact(void * pp,const void ** buf,size_t * size)87 static SRes LookToRead_Look_Exact(void *pp, const void **buf, size_t *size)
88 {
89   SRes res = SZ_OK;
90   CLookToRead *p = (CLookToRead *)pp;
91   size_t size2 = p->size - p->pos;
92   if (size2 == 0 && *size > 0)
93   {
94     p->pos = 0;
95     if (*size > LookToRead_BUF_SIZE)
96       *size = LookToRead_BUF_SIZE;
97     res = p->realStream->Read(p->realStream, p->buf, size);
98     size2 = p->size = *size;
99   }
100   if (size2 < *size)
101     *size = size2;
102   *buf = p->buf + p->pos;
103   return res;
104 }
105 
LookToRead_Skip(void * pp,size_t offset)106 static SRes LookToRead_Skip(void *pp, size_t offset)
107 {
108   CLookToRead *p = (CLookToRead *)pp;
109   p->pos += offset;
110   return SZ_OK;
111 }
112 
LookToRead_Read(void * pp,void * buf,size_t * size)113 static SRes LookToRead_Read(void *pp, void *buf, size_t *size)
114 {
115   CLookToRead *p = (CLookToRead *)pp;
116   size_t rem = p->size - p->pos;
117   if (rem == 0)
118     return p->realStream->Read(p->realStream, buf, size);
119   if (rem > *size)
120     rem = *size;
121   memcpy(buf, p->buf + p->pos, rem);
122   p->pos += rem;
123   *size = rem;
124   return SZ_OK;
125 }
126 
LookToRead_Seek(void * pp,Int64 * pos,ESzSeek origin)127 static SRes LookToRead_Seek(void *pp, Int64 *pos, ESzSeek origin)
128 {
129   CLookToRead *p = (CLookToRead *)pp;
130   p->pos = p->size = 0;
131   return p->realStream->Seek(p->realStream, pos, origin);
132 }
133 
LookToRead_CreateVTable(CLookToRead * p,int lookahead)134 void LookToRead_CreateVTable(CLookToRead *p, int lookahead)
135 {
136   p->s.Look = lookahead ?
137       LookToRead_Look_Lookahead :
138       LookToRead_Look_Exact;
139   p->s.Skip = LookToRead_Skip;
140   p->s.Read = LookToRead_Read;
141   p->s.Seek = LookToRead_Seek;
142 }
143 
LookToRead_Init(CLookToRead * p)144 void LookToRead_Init(CLookToRead *p)
145 {
146   p->pos = p->size = 0;
147 }
148 
SecToLook_Read(void * pp,void * buf,size_t * size)149 static SRes SecToLook_Read(void *pp, void *buf, size_t *size)
150 {
151   CSecToLook *p = (CSecToLook *)pp;
152   return LookInStream_LookRead(p->realStream, buf, size);
153 }
154 
SecToLook_CreateVTable(CSecToLook * p)155 void SecToLook_CreateVTable(CSecToLook *p)
156 {
157   p->s.Read = SecToLook_Read;
158 }
159 
SecToRead_Read(void * pp,void * buf,size_t * size)160 static SRes SecToRead_Read(void *pp, void *buf, size_t *size)
161 {
162   CSecToRead *p = (CSecToRead *)pp;
163   return p->realStream->Read(p->realStream, buf, size);
164 }
165 
SecToRead_CreateVTable(CSecToRead * p)166 void SecToRead_CreateVTable(CSecToRead *p)
167 {
168   p->s.Read = SecToRead_Read;
169 }
170