Refactor Encoding file parsing

Change this into a callback-driven approach so that the logic for
dealing with each individual (glyph index, ucs4) pair is hoisted
out of the parsing code itself. This will allow us to use the same
parser implementation in different scenarios.

1 files changed, 54 insertions, 21 deletions

diff --git a/src/rufl_init.c b/src/rufl_init.c
index a9d2719..b345b75 100644
--- a/src/rufl_init.c
+++ b/src/rufl_init.c
@@ -79,8 +79,12 @@ static rufl_code rufl_init_scan_font_old(unsigned int font_index);
 static rufl_code rufl_init_scan_font_in_encoding(const char *font_name, 
 		const char *encoding, struct rufl_character_set *charset,
 		struct rufl_unicode_map *umap, unsigned int *last);
-static rufl_code rufl_init_read_encoding(font_f font,
+static rufl_code rufl_init_populate_unicode_map(font_f f,
 		struct rufl_unicode_map *umap);
+static rufl_code rufl_init_read_encoding(font_f font,
+		rufl_code (*callback)(void *pw,
+			uint32_t glyph_idx, uint32_t ucs4),
+		void *pw);
 static int rufl_glyph_map_cmp(const void *keyval, const void *datum);
 static int rufl_unicode_map_cmp(const void *z1, const void *z2);
 static rufl_code rufl_init_substitution_table(void);
@@ -935,7 +939,7 @@ rufl_code rufl_init_scan_font_in_encoding(const char *font_name,
 		return rufl_FONT_MANAGER_ERROR;
 	}
 
-	code = rufl_init_read_encoding(font, umap);
+	code = rufl_init_populate_unicode_map(font, umap);
 	if (code != rufl_OK) {
 		LOG("rufl_init_read_encoding(\"%s\", ...): 0x%x",
 				buf, code);
@@ -1003,21 +1007,58 @@ rufl_code rufl_init_scan_font_in_encoding(const char *font_name,
 	return rufl_OK;
 }
 
+static rufl_code rufl_init_umap_cb(void *pw, uint32_t glyph_idx, uint32_t ucs4)
+{
+	struct rufl_unicode_map *umap = pw;
+	rufl_code result = rufl_OK;
+
+	/* Ignore first 32 character codes (these are control chars) */
+	if (glyph_idx > 31 && glyph_idx < 256 && umap->entries < 256) {
+		umap->map[umap->entries].u = ucs4;
+		umap->map[umap->entries].c = glyph_idx;
+		umap->entries++;
+		if (umap->entries == 256)
+			result = rufl_IO_EOF;
+	}
+
+	return result;
+}
 
 /**
- * Parse an encoding file and fill in a rufl_unicode_map.
+ * Populate a unicode map by parsing the font's encoding file
  */
 
-rufl_code rufl_init_read_encoding(font_f font,
+rufl_code rufl_init_populate_unicode_map(font_f f,
 		struct rufl_unicode_map *umap)
 {
+	rufl_code result;
+
+	umap->entries = 0;
+
+	result = rufl_init_read_encoding(f, rufl_init_umap_cb, &umap);
+	if (result == rufl_OK) {
+		/* sort by unicode */
+		qsort(umap->map, umap->entries, sizeof umap->map[0],
+				rufl_unicode_map_cmp);
+	}
+	return result;
+}
+
+/**
+ * Parse an encoding file
+ */
+
+rufl_code rufl_init_read_encoding(font_f font,
+		rufl_code (*callback)(void *pw,
+			uint32_t glyph_idx, uint32_t ucs4),
+		void *pw)
+{
 	enum {
 		STATE_START,
 		STATE_COMMENT,
 		STATE_COLLECT,
 	} state = STATE_START;
-	bool emit = false;
-	unsigned int u = 0;
+	bool emit = false, done = false;
 	unsigned int i = 0;
 	unsigned int n = 0;
 	int c;
@@ -1041,7 +1082,7 @@ rufl_code rufl_init_read_encoding(font_f font,
 	if (!fp)
 		return rufl_IO_ERROR;
 
-	while (!feof(fp) && i < 256 && u < 256) {
+	while (!feof(fp) && !done) {
 		c = fgetc(fp);
 
 		if (state == STATE_START) {
@@ -1083,8 +1124,8 @@ rufl_code rufl_init_read_encoding(font_f font,
 			}
 		}
 
-		/* Ignore first 32 character codes (these are control chars) */
-		if (emit && i > 31 && i < 256 && u < 256) {
+		if (emit) {
+			emit = false;
 			entry = bsearch(s, rufl_glyph_map,
 					rufl_glyph_map_size,
 					sizeof rufl_glyph_map[0],
@@ -1096,28 +1137,20 @@ rufl_code rufl_init_read_encoding(font_f font,
 					entry--;
 				for (; strcmp(s, entry->glyph_name) == 0;
 						entry++) {
-					umap->map[u].u = entry->u;
-					umap->map[u].c = i;
-					u++;
-					if (u == 256)
+					if (callback(pw, i,
+							entry->u) != rufl_OK) {
+						done = true;
 						break;
+					}
 				}
 			}
-		}
-
-		if (emit) {
 			i++;
-			emit = false;
 		}
 	}
 
 	if (fclose(fp) == EOF)
 		return rufl_IO_ERROR;
 
-	/* sort by unicode */
-	qsort(umap->map, u, sizeof umap->map[0], rufl_unicode_map_cmp);
-	umap->entries = u;
-
 	return rufl_OK;
 }