Re: Octstr support for converting to and from HTML 4 entities.

Index: gwlib/octstr.c
===================================================================
RCS file: /home/cvs/gateway/gwlib/octstr.c,v
retrieving revision 1.137
diff -u -r1.137 octstr.c
--- gwlib/octstr.c	4 Sep 2002 09:13:11 -0000	1.137
+++ gwlib/octstr.c	22 Sep 2002 23:28:22 -0000
@@ -1220,7 +1220,7 @@
     
     octstr_grow(ostr, ostr->len + 1);
     if (ostr->len > pos)
-        memmove(ostr->data + 1, ostr->data + pos, ostr->len - pos);
+        memmove(ostr->data + pos + 1, ostr->data + pos, ostr->len - pos);
     memcpy(ostr->data + pos, &c, 1);
     ostr->len += 1;
     ostr->data[ostr->len] = '\0';
@@ -2182,3 +2182,94 @@
 
     return resultcode;
 }
+
+/*
+ * This function is meant to find html entities in an octstr.
+ * The html-entities.def file must be sorted alphabetically for
+ * this function to work (according to C-Locale).
+ * It can be made even faster by implementing a binary search, though
+ * better boundary checking must be done in that case.
+*/
+static int octstr_find_entity(Octstr* input, int startpos, int endpos)
+{
+#define ENTITY(a,b) { a, b },
+    struct entity_struct {
+	    int entity;
+	    char *entity_str;
+    };
+    const struct entity_struct entities[] = {
+#include "html-entities.def"
+	{ -1, "" } /* pivot */
+    };
+#undef ENTITY
+
+    int  loop = 0; /* position of current entity in entity table */
+    int  pos = startpos; /* current position to check in input string */
+    char ch, /* current character in entity-table */
+         current; /* current character in input string */
+
+    current = octstr_get_char(input, pos);
+    while (1) {
+	ch = entities[loop].entity_str[pos - startpos];
+	if (ch == current) {
+	    pos++;
+	    if (pos > endpos) {
+		/* we reached the end of the entity in the input string */
+		return -1; /* not found */
+	    }
+    	    current = octstr_get_char(input, pos);
+	    continue;
+	}
+	if (ch == '\0') {
+	    if (pos == endpos) {
+		/* it seems this is the entity that we are looking for */
+		return entities[loop].entity;
+	    }
+	    /* We are still looking for more entries, in case multiple entries in
+	     * the entity table exist where one entry is equal to the prefix of
+	     * the next (Special case) */
+	}
+	else if (current < ch) {
+	    /* the string in the sorted list is already greater than the string
+	     * that we are looking for. No use to look any further. */
+	    return -1; /* not found */
+	}
+	/* go to next entry in entity table */
+	loop++;
+	if (entities[loop].entity == -1) {
+	    /* Pivot found: we are at the end of the table */
+	    return -1; /* not found */
+	}
+	if (octstr_len(octstr_imm((entities[loop].entity_str))) <= pos - startpos) {
+	    /* Check this in case we encouter the Special case mentioned above */
+	    return -1; /* not found */
+	}
+    }
+    /* never reached */
+}
+
+/*
+ * function octstr_convert_from_html_entities()
+ *   convert HTML safe data back to binary data by replacing HTML entities with their 
+ *   respective character values   
+ * Input: data to be inserted in HTML
+ **/
+void octstr_convert_from_html_entities(Octstr* input)
+{
+    int startpos = 0, endpos;
+    int entity;
+
+    
+    while ((startpos = octstr_search_char(input, '&', startpos)) != -1) {
+	endpos = octstr_search_char(input, ';', startpos + 1);
+	if (endpos >= 0) {
+	    entity = octstr_find_entity(input, startpos + 1, endpos);
+	    if (entity >= 0) {
+	        octstr_delete(input, startpos, endpos - startpos + 1);
+    	        octstr_insert_char(input, startpos, entity);
+	    }
+	}
+	startpos++;
+    }
+}
+