[398] | 1 | #include "stdio_impl.h"
|
---|
| 2 | #include <errno.h>
|
---|
| 3 | #include <string.h>
|
---|
| 4 | #include <inttypes.h>
|
---|
| 5 |
|
---|
| 6 | struct cookie {
|
---|
| 7 | size_t pos, len, size;
|
---|
| 8 | unsigned char *buf;
|
---|
| 9 | int mode;
|
---|
| 10 | };
|
---|
| 11 |
|
---|
| 12 | static off_t mseek(FILE *f, off_t off, int whence)
|
---|
| 13 | {
|
---|
| 14 | ssize_t base;
|
---|
| 15 | struct cookie *c = f->cookie;
|
---|
| 16 | if (whence>2U) {
|
---|
| 17 | fail:
|
---|
| 18 | errno = EINVAL;
|
---|
| 19 | return -1;
|
---|
| 20 | }
|
---|
| 21 | base = (size_t [3]){0, c->pos, c->len}[whence];
|
---|
| 22 | if (off < -base || off > (ssize_t)c->size-base) goto fail;
|
---|
| 23 | return c->pos = base+off;
|
---|
| 24 | }
|
---|
| 25 |
|
---|
| 26 | static size_t mread(FILE *f, unsigned char *buf, size_t len)
|
---|
| 27 | {
|
---|
| 28 | struct cookie *c = f->cookie;
|
---|
| 29 | size_t rem = c->len - c->pos;
|
---|
| 30 | if (c->pos > c->len) rem = 0;
|
---|
| 31 | if (len > rem) {
|
---|
| 32 | len = rem;
|
---|
| 33 | f->flags |= F_EOF;
|
---|
| 34 | }
|
---|
| 35 | memcpy(buf, c->buf+c->pos, len);
|
---|
| 36 | c->pos += len;
|
---|
| 37 | rem -= len;
|
---|
| 38 | if (rem > f->buf_size) rem = f->buf_size;
|
---|
| 39 | f->rpos = f->buf;
|
---|
| 40 | f->rend = f->buf + rem;
|
---|
| 41 | memcpy(f->rpos, c->buf+c->pos, rem);
|
---|
| 42 | c->pos += rem;
|
---|
| 43 | return len;
|
---|
| 44 | }
|
---|
| 45 |
|
---|
| 46 | static size_t mwrite(FILE *f, const unsigned char *buf, size_t len)
|
---|
| 47 | {
|
---|
| 48 | struct cookie *c = f->cookie;
|
---|
| 49 | size_t rem;
|
---|
| 50 | size_t len2 = f->wpos - f->wbase;
|
---|
| 51 | if (len2) {
|
---|
| 52 | f->wpos = f->wbase;
|
---|
| 53 | if (mwrite(f, f->wpos, len2) < len2) return 0;
|
---|
| 54 | }
|
---|
| 55 | if (c->mode == 'a') c->pos = c->len;
|
---|
| 56 | rem = c->size - c->pos;
|
---|
| 57 | if (len > rem) len = rem;
|
---|
| 58 | memcpy(c->buf+c->pos, buf, len);
|
---|
| 59 | c->pos += len;
|
---|
| 60 | if (c->pos > c->len) {
|
---|
| 61 | c->len = c->pos;
|
---|
| 62 | if (c->len < c->size) c->buf[c->len] = 0;
|
---|
| 63 | else if ((f->flags&F_NORD) && c->size) c->buf[c->size-1] = 0;
|
---|
| 64 | }
|
---|
| 65 | return len;
|
---|
| 66 | }
|
---|
| 67 |
|
---|
| 68 | static int mclose(FILE *m)
|
---|
| 69 | {
|
---|
| 70 | return 0;
|
---|
| 71 | }
|
---|
| 72 |
|
---|
| 73 | FILE *fmemopen(void *restrict buf, size_t size, const char *restrict mode)
|
---|
| 74 | {
|
---|
| 75 | FILE *f;
|
---|
| 76 | struct cookie *c;
|
---|
| 77 | int plus = !!strchr(mode, '+');
|
---|
| 78 |
|
---|
| 79 | if (!size || !strchr("rwa", *mode)) {
|
---|
| 80 | errno = EINVAL;
|
---|
| 81 | return 0;
|
---|
| 82 | }
|
---|
| 83 |
|
---|
| 84 | if (!buf && size > SIZE_MAX-sizeof(FILE)-BUFSIZ-UNGET) {
|
---|
| 85 | errno = ENOMEM;
|
---|
| 86 | return 0;
|
---|
| 87 | }
|
---|
| 88 |
|
---|
| 89 | f = calloc(sizeof *f + sizeof *c + UNGET + BUFSIZ + (buf?0:size), 1);
|
---|
| 90 | if (!f) return 0;
|
---|
| 91 | f->cookie = c = (void *)(f+1);
|
---|
| 92 | f->fd = -1;
|
---|
| 93 | f->lbf = EOF;
|
---|
| 94 | f->buf = (unsigned char *)(c+1) + UNGET;
|
---|
| 95 | f->buf_size = BUFSIZ;
|
---|
| 96 | if (!buf) buf = f->buf + BUFSIZ;
|
---|
| 97 |
|
---|
| 98 | c->buf = buf;
|
---|
| 99 | c->size = size;
|
---|
| 100 | c->mode = *mode;
|
---|
| 101 |
|
---|
| 102 | if (!plus) f->flags = (*mode == 'r') ? F_NOWR : F_NORD;
|
---|
| 103 | if (*mode == 'r') c->len = size;
|
---|
| 104 | else if (*mode == 'a') c->len = c->pos = strnlen(buf, size);
|
---|
| 105 |
|
---|
| 106 | f->read = mread;
|
---|
| 107 | f->write = mwrite;
|
---|
| 108 | f->seek = mseek;
|
---|
| 109 | f->close = mclose;
|
---|
| 110 |
|
---|
| 111 | if (!libc.threaded) f->lock = -1;
|
---|
| 112 |
|
---|
| 113 | return __ofl_add(f);
|
---|
| 114 | }
|
---|