ascii_xxx -> chars_xxx (intended to hold more than just ascii encoding).

More html work.

1 files changed, 201 insertions, 0 deletions

diff --git a/chars.c b/chars.c
new file mode 100644
index 00000000..6c2298f0
--- /dev/null
+++ b/chars.c
@@ -0,0 +1,201 @@
+/*	$Id: chars.c,v 1.1 2009/09/17 07:41:28 kristaps Exp $ */
+/*
+ * Copyright (c) 2009 Kristaps Dzonsons <kristaps@kth.se>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+#include <assert.h>
+#include <err.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "chars.h"
+
+#define	ASCII_PRINT_HI	 126
+#define	ASCII_PRINT_LO	 32
+
+struct	ln {
+	struct ln	 *next;
+	const char	 *code;
+	const char	 *out;
+	size_t		  codesz;
+	size_t		  outsz;
+	int		  type;
+#define	CHARS_CHAR	 (1 << 0)
+#define	CHARS_STRING	 (1 << 1)
+#define CHARS_BOTH	 (0x03)
+};
+
+#define	LINES_MAX	  266
+
+#define CHAR(w, x, y, z) \
+	{ NULL, (w), (y), (x), (z), CHARS_CHAR },
+#define STRING(w, x, y, z) \
+	{ NULL, (w), (y), (x), (z), CHARS_STRING },
+#define BOTH(w, x, y, z) \
+	{ NULL, (w), (y), (x), (z), CHARS_BOTH },
+
+static	struct ln lines[LINES_MAX] = {
+#include "chars.in"
+};
+
+struct	tbl {
+	struct ln	**htab;
+};
+
+static	inline int	  match(const struct ln *,
+				const char *, size_t, int);
+static	const char	 *find(struct tbl *, const char *, 
+				size_t, size_t *, int);
+
+
+void
+chars_free(void *arg)
+{
+	struct tbl	*tab;
+
+	tab = (struct tbl *)arg;
+
+	free(tab->htab);
+	free(tab);
+}
+
+
+/* ARGSUSED */
+void *
+chars_init(enum chars type)
+{
+	struct tbl	 *tab;
+	struct ln	**htab;
+	struct ln	 *pp;
+	int		  i, hash;
+
+	/*
+	 * Constructs a very basic chaining hashtable.  The hash routine
+	 * is simply the integral value of the first character.
+	 * Subsequent entries are chained in the order they're processed
+	 * (they're in-line re-ordered during lookup).
+	 */
+
+	if (NULL == (tab = malloc(sizeof(struct tbl))))
+		err(1, "malloc");
+
+	htab = calloc(ASCII_PRINT_HI - ASCII_PRINT_LO + 1, 
+			sizeof(struct ln **));
+
+	if (NULL == htab)
+		err(1, "malloc");
+
+	for (i = 0; i < LINES_MAX; i++) {
+		assert(lines[i].codesz > 0);
+		assert(lines[i].code);
+		assert(lines[i].out);
+
+		hash = (int)lines[i].code[0] - ASCII_PRINT_LO;
+
+		if (NULL == (pp = htab[hash])) {
+			htab[hash] = &lines[i];
+			continue;
+		}
+
+		for ( ; pp->next; pp = pp->next)
+			/* Scan ahead. */ ;
+
+		pp->next = &lines[i];
+	}
+
+	tab->htab = htab;
+	return(tab);
+}
+
+
+const char *
+chars_a2ascii(void *arg, const char *p, size_t sz, size_t *rsz)
+{
+
+	return(find((struct tbl *)arg, p, sz, rsz, CHARS_CHAR));
+}
+
+
+const char *
+chars_a2res(void *arg, const char *p, size_t sz, size_t *rsz)
+{
+
+	return(find((struct tbl *)arg, p, sz, rsz, CHARS_STRING));
+}
+
+
+static const char *
+find(struct tbl *tab, const char *p, size_t sz, size_t *rsz, int type)
+{
+	struct ln	 *pp, *prev;
+	struct ln	**htab;
+	int		  hash;
+
+	assert(p);
+	assert(sz > 0);
+
+	if (p[0] < ASCII_PRINT_LO || p[0] > ASCII_PRINT_HI)
+		return(NULL);
+
+	/*
+	 * Lookup the symbol in the symbol hash.  See ascii2htab for the
+	 * hashtable specs.  This dynamically re-orders the hash chain
+	 * to optimise for repeat hits.
+	 */
+
+	hash = (int)p[0] - ASCII_PRINT_LO;
+	htab = tab->htab;
+
+	if (NULL == (pp = htab[hash]))
+		return(NULL);
+
+	if (NULL == pp->next) {
+		if ( ! match(pp, p, sz, type)) 
+			return(NULL);
+		*rsz = pp->outsz;
+		return(pp->out);
+	}
+
+	for (prev = NULL; pp; pp = pp->next) {
+		if ( ! match(pp, p, sz, type)) {
+			prev = pp;
+			continue;
+		}
+
+		/* Re-order the hash chain. */
+
+		if (prev) {
+			prev->next = pp->next;
+			pp->next = htab[hash];
+			htab[hash] = pp;
+		}
+
+		*rsz = pp->outsz;
+		return(pp->out);
+	}
+
+	return(NULL);
+}
+
+
+static inline int
+match(const struct ln *ln, const char *p, size_t sz, int type)
+{
+
+	if ( ! (ln->type & type))
+		return(0);
+	if (ln->codesz != sz)
+		return(0);
+	return(0 == strncmp(ln->code, p, sz));
+}