1#include "stdio_impl.h" 2#include <wchar.h> 3#include <errno.h> 4#include <limits.h> 5#include <string.h> 6 7struct cookie { 8 wchar_t **bufp; 9 size_t *sizep; 10 size_t pos; 11 wchar_t *buf; 12 size_t len; 13 size_t space; 14 mbstate_t mbs; 15}; 16 17static off_t wms_seek(FILE *f, off_t off, int whence) 18{ 19 ssize_t base; 20 struct cookie *c = f->cookie; 21 if (whence>2U) { 22fail: 23 errno = EINVAL; 24 return -1; 25 } 26 base = (size_t [3]){0, c->pos, c->len}[whence]; 27 if (off < -base || off > SSIZE_MAX/4-base) goto fail; 28 memset(&c->mbs, 0, sizeof c->mbs); 29 return c->pos = base+off; 30} 31 32static size_t wms_write(FILE *f, const unsigned char *buf, size_t len) 33{ 34 struct cookie *c = f->cookie; 35 size_t len2; 36 wchar_t *newbuf; 37 if (len + c->pos >= c->space) { 38 len2 = 2*c->space+1 | c->pos+len+1; 39 if (len2 > SSIZE_MAX/4) return 0; 40 newbuf = realloc(c->buf, len2*4); 41 if (!newbuf) return 0; 42 *c->bufp = c->buf = newbuf; 43 memset(c->buf + c->space, 0, 4*(len2 - c->space)); 44 c->space = len2; 45 } 46 47 len2 = mbsnrtowcs(c->buf+c->pos, (void *)&buf, len, c->space-c->pos, &c->mbs); 48 if (len2 == -1) return 0; 49 c->pos += len2; 50 if (c->pos >= c->len) c->len = c->pos; 51 *c->sizep = c->pos; 52 return len; 53} 54 55static int wms_close(FILE *f) 56{ 57 return 0; 58} 59 60FILE *open_wmemstream(wchar_t **bufp, size_t *sizep) 61{ 62 FILE *f; 63 struct cookie *c; 64 wchar_t *buf; 65 66 if (!(f=malloc(sizeof *f + sizeof *c))) return 0; 67 if (!(buf=malloc(sizeof *buf))) { 68 free(f); 69 return 0; 70 } 71 memset(f, 0, sizeof *f + sizeof *c); 72 f->cookie = c = (void *)(f+1); 73 74 c->bufp = bufp; 75 c->sizep = sizep; 76 c->pos = c->len = c->space = *sizep = 0; 77 c->buf = *bufp = buf; 78 *buf = 0; 79 80 f->flags = F_NORD; 81 f->fd = -1; 82 f->buf = (void *)(c+1); 83 f->buf_size = 0; 84 f->lbf = EOF; 85 f->write = wms_write; 86 f->seek = wms_seek; 87 f->close = wms_close; 88 89 if (!libc.threaded) f->lock = -1; 90 91 return __ofl_add(f); 92} 93