/* Copyright (C) 2004 Manuel Novoa III <mjn3@codepoet.org> * * GNU Library General Public License (LGPL) version 2 or later. * * Dedicated to Toni. See uClibc/DEDICATION.mjn3 for details. */ #include <features.h> #ifdef __USE_GNU #include "_stdio.h" #ifndef __UCLIBC_HAS_GLIBC_CUSTOM_STREAMS__ #error no custom streams! #endif #define COOKIE ((__oms_cookie *) cookie) #define MEMSTREAM_BUFSIZ 256 typedef struct { char *buf; size_t len; size_t pos; size_t eof; char **bufloc; size_t *sizeloc; } __oms_cookie; /* Nothing to do here, as memstreams are write-only. */ /* static ssize_t oms_read(void *cookie, char *buf, size_t bufsize) */ /* { */ /* } */ static ssize_t oms_write(register void *cookie, const char *buf, size_t bufsize) { register char *newbuf; size_t count; /* Note: we already know bufsize < SSIZE_MAX... */ count = COOKIE->len - COOKIE->pos - 1; assert(COOKIE->pos < COOKIE->len); /* Always nul-terminate! */ if (bufsize > count) { newbuf = realloc(COOKIE->buf, COOKIE->len + bufsize - count); if (newbuf) { *COOKIE->bufloc = COOKIE->buf = newbuf; COOKIE->len += (bufsize - count); } else { bufsize = count; if (count == 0) { __set_errno(EFBIG); /* TODO: check glibc errno setting... */ return -1; } } } memcpy(COOKIE->buf + COOKIE->pos, buf, bufsize); COOKIE->pos += bufsize; if (COOKIE->pos > COOKIE->eof) { *COOKIE->sizeloc = COOKIE->eof = COOKIE->pos; COOKIE->buf[COOKIE->eof] = 0; /* Need to nul-terminate. */ } return bufsize; } static int oms_seek(register void *cookie, __offmax_t *pos, int whence) { __offmax_t p = *pos; register char *buf; size_t leastlen; /* Note: fseek already checks that whence is legal, so don't check here * unless debugging. */ assert(((unsigned int) whence) <= 2); if (whence != SEEK_SET) { p += (whence == SEEK_CUR) ? COOKIE->pos : /* SEEK_END */ COOKIE->eof; } /* Note: glibc only allows seeking in the buffer. We'll actually restrict * to the data. */ /* Check for offset < 0, offset >= too big (need nul), or overflow... */ if (((uintmax_t) p) >= SIZE_MAX - 1) { return -1; } leastlen = ((size_t) p) + 1; /* New pos + 1 for nul if necessary. */ if (leastlen >= COOKIE->len) { /* Need to grow buffer... */ buf = realloc(COOKIE->buf, leastlen); if (buf) { *COOKIE->bufloc = COOKIE->buf = buf; COOKIE->len = leastlen; memset(buf + COOKIE->eof, 0, leastlen - COOKIE->eof); /* 0-fill */ } else { /* TODO: check glibc errno setting... */ return -1; } } *pos = COOKIE->pos = --leastlen; if (leastlen > COOKIE->eof) { memset(COOKIE->buf + COOKIE->eof, 0, leastlen - COOKIE->eof); *COOKIE->sizeloc = COOKIE->eof; } return 0; } static int oms_close(void *cookie) { free(cookie); return 0; } #undef COOKIE static const cookie_io_functions_t _oms_io_funcs = { NULL, oms_write, oms_seek, oms_close }; /* TODO: If we have buffers enabled, it might be worthwile to add a pointer * to the FILE in the cookie and operate directly on the buffer itself * (ie replace the FILE buffer with the cookie buffer and update FILE bufstart, * etc. whenever we seek). */ FILE *open_memstream(char **bufloc, size_t *sizeloc) { register __oms_cookie *cookie; register FILE *fp; if ((cookie = malloc(sizeof(__oms_cookie))) != NULL) { if ((cookie->buf = malloc(cookie->len = MEMSTREAM_BUFSIZ)) == NULL) { goto EXIT_cookie; } *cookie->buf = 0; /* Set nul terminator for buffer. */ *(cookie->bufloc = bufloc) = cookie->buf; *(cookie->sizeloc = sizeloc) = cookie->eof = cookie->pos = 0; #ifndef __BCC__ fp = fopencookie(cookie, "w", _oms_io_funcs); #else fp = fopencookie(cookie, "w", &_oms_io_funcs); #endif /* Note: We don't need to worry about locking fp in the thread case * as the only possible access would be a close or flush with * nothing currently in the FILE's write buffer. */ if (fp != NULL) { __STDIO_STREAM_VALIDATE(fp); return fp; } } free(cookie->buf); EXIT_cookie: free(cookie); return NULL; } libc_hidden_def(open_memstream) #endif