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121 lines
2.5 KiB
121 lines
2.5 KiB
3 months ago
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/*
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* UCW Library -- Fast Buffered I/O on Static Buffers
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*
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* (c) 2003--2006 Martin Mares <mj@ucw.cz>
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*
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* This software may be freely distributed and used according to the terms
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* of the GNU Lesser General Public License.
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*/
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#include <ucw/lib.h>
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#include <ucw/fastbuf.h>
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#include <stdio.h>
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#include <stdlib.h>
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static int
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fbbuf_refill(struct fastbuf *f)
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{
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f->bstop = f->bufend;
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f->pos = f->bstop - f->buffer;
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return f->bptr < f->bstop;
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}
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static int
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fbbuf_seek(struct fastbuf *f, ucw_off_t pos, int whence)
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{
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/* Somebody might want to seek to the end of buffer, try to be nice to him. */
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ucw_off_t len = f->bufend - f->buffer;
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if (whence == SEEK_END)
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pos += len;
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if (pos < 0 || pos > len)
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bthrow(f, "seek", "Seek out of range");
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f->bstop = f->bptr = f->buffer + pos;
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f->pos = pos;
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return 1;
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}
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void
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fbbuf_init_read(struct fastbuf *f, byte *buf, uint size, uint can_overwrite)
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{
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*f = (struct fastbuf) {
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.buffer = buf,
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.bptr = buf,
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.bstop = buf + size,
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.bufend = buf + size,
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.name = "fbbuf-read",
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.pos = size,
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.refill = fbbuf_refill,
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.seek = fbbuf_seek,
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.can_overwrite_buffer = can_overwrite
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};
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}
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static void
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fbbuf_spout(struct fastbuf *f)
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{
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if (f->bptr >= f->bufend)
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bthrow(f, "write", "fbbuf: buffer overflow on write");
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}
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void
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fbbuf_init_write(struct fastbuf *f, byte *buf, uint size)
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{
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*f = (struct fastbuf) {
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.buffer = buf,
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.bstop = buf,
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.bptr = buf,
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.bufend = buf + size,
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.name = "fbbuf-write",
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.spout = fbbuf_spout,
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};
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}
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#ifdef TEST
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int main(int argc, char *argv[])
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{
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if (argc < 2)
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{
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fprintf(stderr, "You must specify a test (r, w, o)\n");
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return 1;
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}
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switch (*argv[1])
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{
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case 'r':
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{
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struct fastbuf fb;
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char *data = "Two\nlines\n";
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fbbuf_init_read(&fb, data, strlen(data), 0);
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char buffer[10];
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while (bgets(&fb, buffer, 10))
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puts(buffer);
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bclose(&fb);
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break;
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}
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case 'w':
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{
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struct fastbuf fb;
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char buff[20];
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fbbuf_init_write(&fb, buff, 20);
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bputs(&fb, "Hello world\n");
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bputc(&fb, 0);
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fputs(buff, stdout);
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break;
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}
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case 'o':
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{
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struct fastbuf fb;
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char buff[4];
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fbbuf_init_write(&fb, buff, 4);
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bputs(&fb, "Hello");
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bputc(&fb, 0);
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fputs(buff, stdout);
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break;
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}
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}
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return 0;
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}
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#endif
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