universe@56: #include "memstream.h"
universe@56: #include <stdarg.h>
universe@56: #include <stdlib.h>
universe@56: #include <string.h>
universe@56: 
universe@56: struct _UcxMemstream {
universe@56:     void *space;
universe@56:     size_t pos;
universe@56:     size_t length;
universe@56:     _Bool autofree;
universe@56: };
universe@56: 
universe@56: UcxMemstream *ucx_memopen(void* space, size_t length) {
universe@56:     UcxMemstream *stream = (UcxMemstream*) malloc(sizeof(UcxMemstream));
universe@56:     if (stream) {
universe@56:         if (!space) {
universe@56:             stream->space = malloc(length);
universe@56:             if (!stream->space) {
universe@56:                 free(stream);
universe@56:                 return NULL;
universe@56:             }
universe@56:             memset(stream->space, 0, length);
universe@56:             stream->autofree = 1;
universe@56:         } else {
universe@56:             stream->space = space;
universe@56:             stream->autofree = 0;
universe@56:         }
universe@56:         stream->length = length;
universe@56: 
universe@56:         stream->pos = 0;
universe@56:     }
universe@56: 
universe@56:     return stream;
universe@56: }
universe@56: 
universe@56: void ucx_memclose(UcxMemstream *stream) {
universe@56:     if (stream->autofree) {
universe@56:         free(stream->space);
universe@56:     }
universe@56:     free(stream);
universe@56: }
universe@56: 
universe@56: int ucx_memseek(UcxMemstream *stream, long offset, int whence) {
universe@56:     size_t npos;
universe@56:     switch (whence) {
universe@56:     case SEEK_SET:
universe@56:         npos = 0;
universe@56:         break;
universe@56:     case SEEK_CUR:
universe@56:         npos = stream->pos;
universe@56:         break;
universe@56:     case SEEK_END:
universe@56:         npos = strlen(stream->space);
universe@56:         break;
universe@56:     }
universe@56: 
universe@56:     npos += offset;
universe@56: 
universe@56:     if (npos < 0 || npos > stream->length) {
universe@56:         return -1;
universe@56:     } else {
universe@56:         stream->pos = npos;
universe@56:         return 0;
universe@56:     }
universe@56: 
universe@56: }
universe@56: 
universe@56: int ucx_memeof(UcxMemstream *stream) {
universe@56:     return stream->pos >= stream->length;
universe@56: }
universe@56: 
universe@56: int ucx_memoverflow(UcxMemstream *stream) {
universe@56:     return stream->pos > stream->length;
universe@56: }
universe@56: 
universe@56: size_t ucx_memtell(UcxMemstream *stream) {
universe@56:     return stream->pos;
universe@56: }
universe@56: 
universe@56: size_t ucx_memio(void* d, size_t s, size_t n, UcxMemstream *m, _Bool read) {
universe@56:     size_t len;
universe@56:     if (m->pos + s*n > m->length) {
universe@56:         if (ucx_memoverflow(m)) {
universe@56:             len = 0;
universe@56:         } else {
universe@56:             len = m->length - m->pos;
universe@56:             if (s > 1) len -= len%s;
universe@56:         }
universe@56:     } else {
universe@56:         len = s*n;
universe@56:     }
universe@56: 
universe@56:     if (len == 0) {
universe@56:         return 0;
universe@56:     }
universe@56: 
universe@56:     if (read) {
universe@56:         memcpy(d, m->space+m->pos, len);
universe@56:     } else {
universe@56:         memcpy(m->space+m->pos, d, len);
universe@56:     }
universe@56:     m->pos += len;
universe@56: 
universe@56:     return len;
universe@56: }
universe@56: 
universe@56: int ucx_memputc(UcxMemstream *stream, int c) {
universe@56:     if (ucx_memeof(stream)) {
universe@56:         return EOF;
universe@56:     } else {
universe@56:         c &= 0xFF;
universe@56:         ((char*)(stream->space))[stream->pos] = (char) c;
universe@56:         stream->pos++;
universe@56:         return c;
universe@56:     }
universe@56: }
universe@56: 
universe@56: int ucx_memgetc(UcxMemstream *stream) {
universe@56:     if (ucx_memeof(stream)) {
universe@56:         return EOF;
universe@56:     } else {
universe@56:         int c = ((char*)(stream->space))[stream->pos];
universe@56:         stream->pos++;
universe@56:         return c;
universe@56:     }
universe@56: }
universe@56: 
universe@56: int ucx_memprintf(UcxMemstream *stream, const char* format, ...) {
universe@56:     va_list v;
universe@56:     va_start(v, format);
universe@56:     int r = vsprintf(stream->space+stream->pos, format, v);
universe@56:     va_end(v);
universe@56: 
universe@56:     stream->pos += r;
universe@56: 
universe@56:     return r;
universe@56: }
universe@56: 
universe@56: int ucx_memscanf(UcxMemstream *stream, const char* format, ...) {
universe@56: 
universe@56:     /* TODO: vsscanf returns the number of fields read,
universe@56:      * we need the number of bytes */
universe@56: 
universe@56:     va_list v;
universe@56:     va_start(v, format);
universe@56:     int r = vsscanf(stream->space+stream->pos, format, v);
universe@56:     va_end(v);
universe@56: 
universe@56:     stream->pos += r;
universe@56: 
universe@56:     return r;
universe@56: }