conf-context conf-alloc conf-dump conf-input conf-intr conf-journal conf-parse conf-section conf-getopt \
ipaccess \
fastbuf ff-binary ff-string ff-printf ff-unicode ff-stkstring \
- fb-file fb-mem fb-temp tempfile fb-mmap fb-limfd fb-buffer fb-grow fb-pool fb-atomic fb-param fb-socket \
+ fb-file fb-mem fb-temp tempfile fb-mmap fb-limfd fb-buffer fb-grow fb-pool fb-atomic fb-param fb-socket fb-multi \
char-cat char-upper char-lower unicode stkstring \
wildmatch regex \
prime primetable random \
slists.test bbuf.test kmp-test.test getopt.test ff-unicode.test eltpool.test \
fb-socket.test trie-test.test string.test sha1.test asort-test.test binheap-test.test \
redblack-test.test fb-file.test fb-grow.test fb-pool.test fb-atomic.test \
- fb-limfd.test fb-temp.test fb-mem.test fb-buffer.test fb-mmap.test url.test strtonum-test.test \
+ fb-limfd.test fb-temp.test fb-mem.test fb-buffer.test fb-mmap.test fb-multi.test url.test strtonum-test.test \
gary.test time.test crc.test)
$(o)/ucw/regex.test: $(o)/ucw/regex-t
$(o)/ucw/redblack-test.test: $(o)/ucw/redblack-test
$(o)/ucw/strtonum-test.test: $(o)/ucw/strtonum-test
$(addprefix $(o)/ucw/fb-,file.test grow.test pool.test socket.test atomic.test \
- limfd.test temp.test mem.test buffer.test mmap.test): %.test: %-t
+ limfd.test temp.test mem.test buffer.test mmap.test multi.test): %.test: %-t
$(o)/ucw/url.test: $(o)/ucw/url-t
$(o)/ucw/gary.test: $(o)/ucw/gary-t
$(o)/ucw/time.test: $(o)/ucw/time-conf-t
fbatomic_internal_write(b);
}
+/***
+ * === Fastbufs atop other fastbufs [[fbmulti]]
+ *
+ * Imagine some code which does massive string processing. It takes an input
+ * buffer, writes a part of it into an output buffer, then some other string
+ * and then the remaining part of the input buffer. Or anything else where you
+ * copy all the data at each stage of the complicated process.
+ *
+ * This backend takes multiple fastbufs and concatenates them formally into
+ * one. You may then read them consecutively as they were one fastbuf at all.
+ *
+ * This backend is read-only.
+ *
+ * This backend is seekable iff all of the supplied fastbufs are seekable.
+ *
+ * Please note that no cleanup of underlying fastbufs is provided.
+ *
+ * Also, please be aware of direct operations on the underlying buffers. The
+ * fbmulti backend doesn't expect it.
+ *
+ * The last parameter must be NULL.
+ ***/
+
+struct fastbuf* fbmulti_create(uns bufsize, ...) SENTINEL_CHECK;
+
/*** === Configuring stream parameters [[bconfig]] ***/
enum bconfig_type { /** Parameters that could be configured. **/
--- /dev/null
+/*
+ * UCW Library -- Fast Buffered I/O on itself
+ *
+ * (c) 2012 Jan Moskyto Matejka <mq@ucw.cz>
+ *
+ * This software may be freely distributed and used according to the terms
+ * of the GNU Lesser General Public License.
+ */
+
+#include <ucw/lib.h>
+#include <ucw/clists.h>
+#include <ucw/fastbuf.h>
+#include <ucw/mempool.h>
+
+#include <stdio.h>
+
+struct fb_multi {
+ struct fastbuf fb;
+ struct mempool* mp;
+ struct subbuf* cur;
+ ucw_off_t len;
+ clist* subbufs;
+};
+#define FB_MULTI(f) ((struct fb_multi *)(f))
+
+struct subbuf {
+ cnode n;
+ ucw_off_t begin, end;
+ struct fastbuf* fb;
+};
+#define SUBBUF(f) ((struct subbuf *)(f))
+
+static inline void
+fbmulti_subbuf_get_end(struct subbuf *s)
+{
+ if (s->fb->seek) {
+ bseek(s->fb, 0, SEEK_END);
+ s->end = s->begin + btell(s->fb);
+ }
+}
+
+static inline int
+fbmulti_subbuf_next(struct fastbuf *f)
+{
+ struct subbuf* next = clist_next(FB_MULTI(f)->subbufs, &FB_MULTI(f)->cur->n);
+ if (next == NULL)
+ return 0;
+
+ if (f->seek)
+ next->begin = FB_MULTI(f)->cur->end;
+ FB_MULTI(f)->cur = next;
+ return 1;
+}
+
+static int
+fbmulti_refill(struct fastbuf *f)
+{
+ if (f->bufend == f->bstop)
+ f->bptr = f->bstop = f->buffer;
+ uns len = bread(FB_MULTI(f)->cur->fb, f->bstop, (f->bufend - f->bstop));
+ f->bstop += len;
+ f->pos += len;
+ if (len)
+ return len;
+
+ // Current buf returned EOF
+ // Update the information on end of this buffer
+ fbmulti_subbuf_get_end(FB_MULTI(f)->cur);
+
+ // Take the next one if exists
+ if (fbmulti_subbuf_next(f))
+ return fbmulti_refill(f);
+ else
+ return 0;
+}
+
+static void
+fbmulti_get_len(struct fastbuf *f)
+{
+ ASSERT (f->seek);
+ FB_MULTI(f)->len = 0;
+
+ CLIST_FOR_EACH(struct subbuf *, n, *(FB_MULTI(f)->subbufs))
+ {
+ n->begin = FB_MULTI(f)->len;
+ fbmulti_subbuf_get_end(n);
+ FB_MULTI(f)->len = n->end;
+ }
+}
+
+static int
+fbmulti_seek(struct fastbuf *f, ucw_off_t pos, int whence)
+{
+ switch(whence)
+ {
+ case SEEK_SET:
+ if (f->pos > pos) {
+ FB_MULTI(f)->cur = clist_head(FB_MULTI(f)->subbufs);
+ FB_MULTI(f)->cur->begin = 0;
+ f->pos = 0;
+ return fbmulti_seek(f, pos, SEEK_SET);
+ }
+
+ do {
+ fbmulti_subbuf_get_end(FB_MULTI(f)->cur);
+ if (pos < FB_MULTI(f)->cur->end)
+ break;
+
+ if (!fbmulti_subbuf_next(f))
+ bthrow(f, "seek", "Seek out of range");
+
+ } while (1);
+
+ bseek(FB_MULTI(f)->cur->fb, (pos - FB_MULTI(f)->cur->begin), SEEK_SET);
+ f->pos = pos;
+ f->bptr = f->bstop = f->buffer;
+ return 1;
+ break;
+
+ case SEEK_END:
+ fbmulti_get_len(f);
+ return fbmulti_seek(f, FB_MULTI(f)->len+pos, SEEK_CUR);
+ break;
+
+ default:
+ ASSERT(0);
+ }
+}
+
+static void
+fbmulti_update_capability(struct fastbuf *f) {
+ // FB Multi is only a proxy to other fastbufs ... if any of them lacks
+ // support of any feature, FB Multi also provides no support of that feature
+ f->refill = fbmulti_refill;
+ f->seek = fbmulti_seek;
+
+ CLIST_FOR_EACH(struct subbuf *, n, *(FB_MULTI(f)->subbufs)) {
+ if (!n->fb->refill)
+ f->refill = NULL;
+
+ if (!n->fb->seek)
+ f->seek = NULL;
+ }
+}
+
+struct fastbuf*
+fbmulti_create(uns bufsize, ...)
+{
+ struct mempool *mp = mp_new(bufsize);
+ struct fastbuf *fb_out = mp_alloc(mp, sizeof(struct fb_multi));
+ FB_MULTI(fb_out)->mp = mp;
+
+ struct fastbuf *fb_in;
+ clist* subbufs = mp_alloc(mp, sizeof(clist));
+ clist_init(subbufs);
+ FB_MULTI(fb_out)->subbufs = subbufs;
+
+ va_list args;
+ va_start(args, bufsize);
+ while (fb_in = va_arg(args, struct fastbuf *)) {
+ struct subbuf *sb = mp_alloc(mp, sizeof(struct subbuf));
+ sb->fb = fb_in;
+ clist_add_tail(subbufs, &(sb->n));
+ }
+ va_end(args);
+
+ FB_MULTI(fb_out)->cur = clist_head(subbufs);
+
+ fb_out->buffer = mp_alloc(mp, bufsize);
+ fb_out->bptr = fb_out->bstop = fb_out->buffer;
+ fb_out->bufend = fb_out->buffer + bufsize;
+ fb_out->name = "<multi>";
+
+ fbmulti_update_capability(fb_out);
+
+ return fb_out;
+}
+
+#ifdef TEST
+
+int main(int argc, char ** argv)
+{
+ if (argc < 2)
+ {
+ fprintf(stderr, "You must specify a test (r, w, o)\n");
+ return 1;
+ }
+ switch (*argv[1])
+ {
+ case 'r':
+ {
+ char *data[] = { "One\nLine", "Two\nLines", "Th\nreeLi\nnes\n" };
+ struct fastbuf fb[ARRAY_SIZE(data)];
+ for (uns i=0;i<ARRAY_SIZE(data);i++)
+ fbbuf_init_read(&fb[i], data[i], strlen(data[i]), 0);
+
+ struct fastbuf* f = fbmulti_create(4, &fb[0], &fb[1], &fb[2], NULL);
+
+ char buffer[9];
+ while (bgets(f, buffer, 9))
+ puts(buffer);
+
+ bclose(f);
+ break;
+ }
+ case 'm':
+ {
+ char *data[] = { "Mnl", "ige" };
+ struct fastbuf fb[ARRAY_SIZE(data)];
+ for (uns i=0;i<ARRAY_SIZE(data);i++)
+ fbbuf_init_read(&fb[i], data[i], strlen(data[i]), 0);
+
+ struct fastbuf* f = fbmulti_create(4, &fb[0], &fb[1], NULL);
+
+ int pos[] = {0, 3, 1, 4, 2, 5};
+
+ for (uns i=0;i<ARRAY_SIZE(pos);i++) {
+ bseek(f, pos[i], SEEK_SET);
+ putchar(bgetc(f));
+ }
+
+ bclose(f);
+ break;
+ }
+ }
+ return 0;
+}
+
+#endif
projects / libucw.git / commitdiff