1 /*
2 Copyright 1999-2020 ImageMagick Studio LLC, a non-profit organization
3 dedicated to making software imaging solutions freely available.
4
5 You may not use this file except in compliance with the License. You may
6 obtain a copy of the License at
7
8 https://imagemagick.org/script/license.php
9
10 Unless required by applicable law or agreed to in writing, software
11 distributed under the License is distributed on an "AS IS" BASIS,
12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 See the License for the specific language governing permissions and
14 limitations under the License.
15 */
16 #ifndef MAGICK_BYTE_BUFFER_PRIVATE_H
17 #define MAGICK_BYTE_BUFFER_PRIVATE_H
18
19 #include "MagickCore/blob.h"
20
21 typedef struct _MagickByteBuffer
22 {
23 Image
24 *image;
25
26 ssize_t
27 offset,
28 count;
29
30 unsigned char
31 data[MagickMinBufferExtent];
32 } MagickByteBuffer;
33
ReadMagickByteBuffer(MagickByteBuffer * buffer)34 static inline int ReadMagickByteBuffer(MagickByteBuffer *buffer)
35 {
36 if ((buffer->offset == buffer->count) && (buffer->offset > 0))
37 {
38 if (buffer->count != (ssize_t) sizeof(buffer->data)-1)
39 return(EOF);
40 buffer->offset=0;
41 buffer->count=0;
42 }
43 if ((buffer->offset == 0) && (buffer->count == 0))
44 {
45 buffer->count=ReadBlob(buffer->image,sizeof(buffer->data)-1,
46 buffer->data);
47 if (buffer->count < 1)
48 return(EOF);
49 }
50 return(buffer->data[buffer->offset++]);
51 }
52
GetMagickByteBufferDatum(MagickByteBuffer * buffer)53 static inline char *GetMagickByteBufferDatum(MagickByteBuffer *buffer)
54 {
55 ssize_t
56 count,
57 i;
58
59 if (buffer->offset != 0)
60 {
61 i=0;
62 while (buffer->offset < buffer->count)
63 buffer->data[i++]=buffer->data[buffer->offset++];
64 count=ReadBlob(buffer->image,sizeof(buffer->data)-1-i,buffer->data+i);
65 buffer->count=i;
66 if (count > 0)
67 buffer->count+=count;
68 buffer->offset=0;
69 }
70 return((char *) buffer->data);
71 }
72
CheckMagickByteBuffer(MagickByteBuffer * buffer,const size_t length)73 static void CheckMagickByteBuffer(MagickByteBuffer *buffer,
74 const size_t length)
75 {
76 if ((buffer->offset+length) > (ssize_t) sizeof(buffer->data))
77 (void) GetMagickByteBufferDatum(buffer);
78 }
79
CompareMagickByteBuffer(MagickByteBuffer * buffer,const char * p,const size_t length)80 static MagickBooleanType CompareMagickByteBuffer(MagickByteBuffer *buffer,
81 const char *p,const size_t length)
82 {
83 const char
84 *q;
85
86 CheckMagickByteBuffer(buffer,length);
87 q=(const char *) buffer->data+buffer->offset;
88 if (LocaleNCompare(p,q,length) != 0)
89 return(MagickFalse);
90 return(MagickTrue);
91 }
92
SkipMagickByteBuffer(MagickByteBuffer * buffer,const size_t length)93 static inline void SkipMagickByteBuffer(MagickByteBuffer *buffer,
94 const size_t length)
95 {
96 CheckMagickByteBuffer(buffer,length);
97 if ((ssize_t) (buffer->offset+length) < buffer->count)
98 buffer->offset+=length;
99 }
100
101 #endif
102