comparison: ucx/memstream.c
ucx/memstream.c
- changeset 60
- abae4669fba7
- parent 58
- 733f22fca61a
equal
deleted
inserted
replaced
| 59:c80c910fe191 | 60:abae4669fba7 |
|---|---|
| 1 #include "memstream.h" | |
| 2 #include <stdarg.h> | |
| 3 #include <stdlib.h> | |
| 4 #include <string.h> | |
| 5 | |
| 6 struct UcxMemstream { | |
| 7 void *space; | |
| 8 off_t pos; | |
| 9 size_t length; | |
| 10 _Bool autofree; | |
| 11 }; | |
| 12 | |
| 13 UcxMemstream *ucx_memopen(void *space, size_t length) { | |
| 14 UcxMemstream *stream = (UcxMemstream*) malloc(sizeof(UcxMemstream)); | |
| 15 if (stream) { | |
| 16 if (!space) { | |
| 17 stream->space = malloc(length); | |
| 18 if (!stream->space) { | |
| 19 free(stream); | |
| 20 return NULL; | |
| 21 } | |
| 22 memset(stream->space, 0, length); | |
| 23 stream->autofree = 1; | |
| 24 } else { | |
| 25 stream->space = space; | |
| 26 stream->autofree = 0; | |
| 27 } | |
| 28 stream->length = length; | |
| 29 | |
| 30 stream->pos = 0; | |
| 31 } | |
| 32 | |
| 33 return stream; | |
| 34 } | |
| 35 | |
| 36 void ucx_memclose(UcxMemstream *stream) { | |
| 37 if (stream->autofree) { | |
| 38 free(stream->space); | |
| 39 } | |
| 40 free(stream); | |
| 41 } | |
| 42 | |
| 43 int ucx_memseek(UcxMemstream *stream, off_t offset, int whence) { | |
| 44 off_t npos; | |
| 45 switch (whence) { | |
| 46 case SEEK_SET: | |
| 47 npos = 0; | |
| 48 break; | |
| 49 case SEEK_CUR: | |
| 50 npos = stream->pos; | |
| 51 break; | |
| 52 case SEEK_END: | |
| 53 npos = strlen(stream->space); | |
| 54 break; | |
| 55 } | |
| 56 | |
| 57 npos += offset; | |
| 58 | |
| 59 if (npos < 0 || npos > stream->length) { | |
| 60 return -1; | |
| 61 } else { | |
| 62 stream->pos = npos; | |
| 63 return 0; | |
| 64 } | |
| 65 | |
| 66 } | |
| 67 | |
| 68 int ucx_memeof(UcxMemstream *stream) { | |
| 69 return stream->pos >= stream->length; | |
| 70 } | |
| 71 | |
| 72 size_t ucx_memtell(UcxMemstream *stream) { | |
| 73 return stream->pos; | |
| 74 } | |
| 75 | |
| 76 size_t ucx_memio(void* d, size_t s, size_t n, UcxMemstream *m, _Bool read) { | |
| 77 size_t len; | |
| 78 if (m->pos + s*n > m->length) { | |
| 79 len = m->length - m->pos; | |
| 80 if (s > 1) len -= len%s; | |
| 81 } else { | |
| 82 len = s*n; | |
| 83 } | |
| 84 | |
| 85 if (len == 0) { | |
| 86 return 0; | |
| 87 } | |
| 88 | |
| 89 if (read) { | |
| 90 memcpy(d, (char*)m->space+m->pos, len); | |
| 91 } else { | |
| 92 memcpy((char*)m->space+m->pos, d, len); | |
| 93 } | |
| 94 m->pos += len; | |
| 95 | |
| 96 return len; | |
| 97 } | |
| 98 | |
| 99 int ucx_memputc(UcxMemstream *stream, int c) { | |
| 100 if (ucx_memeof(stream)) { | |
| 101 return EOF; | |
| 102 } else { | |
| 103 c &= 0xFF; | |
| 104 ((char*)(stream->space))[stream->pos] = (char) c; | |
| 105 stream->pos++; | |
| 106 return c; | |
| 107 } | |
| 108 } | |
| 109 | |
| 110 int ucx_memgetc(UcxMemstream *stream) { | |
| 111 if (ucx_memeof(stream)) { | |
| 112 return EOF; | |
| 113 } else { | |
| 114 int c = ((char*)(stream->space))[stream->pos]; | |
| 115 stream->pos++; | |
| 116 return c; | |
| 117 } | |
| 118 } |
