Remember the md5 digest in the fz_font struct.

4 files changed, 23 insertions, 14 deletions

diff --git a/source/fitz/font-imp.h b/source/fitz/font-imp.h
index 74a25ccf..f121923c 100644
--- a/source/fitz/font-imp.h
+++ b/source/fitz/font-imp.h
@@ -39,6 +39,10 @@ struct fz_font_s
 
 	/* cached encoding lookup */
 	uint16_t *encoding_cache[256];
+
+	/* cached md5sum for caching */
+	int has_digest;
+	unsigned char digest[16];
 };
 
 #endif
diff --git a/source/fitz/font.c b/source/fitz/font.c
index 2075306e..c39174ee 100644
--- a/source/fitz/font.c
+++ b/source/fitz/font.c
@@ -1814,3 +1814,15 @@ fz_shaper_data_t *fz_font_shaper_data(fz_context *ctx, fz_font *font)
 {
 	return font ? &font->shaper_data : NULL;
 }
+
+void fz_font_digest(fz_context *ctx, fz_font *font, unsigned char digest[16])
+{
+	if (!font->buffer)
+		fz_throw(ctx, FZ_ERROR_GENERIC, "no font file for digest");
+	if (!font->has_digest)
+	{
+		fz_md5_buffer(ctx, font->buffer, font->digest);
+		font->has_digest = 1;
+	}
+	memcpy(digest, font->digest, 16);
+}
diff --git a/source/pdf/pdf-font.c b/source/pdf/pdf-font.c
index 72e2a971..f600fc1b 100644
--- a/source/pdf/pdf-font.c
+++ b/source/pdf/pdf-font.c
@@ -2010,7 +2010,7 @@ pdf_add_cid_font(fz_context *ctx, pdf_document *doc, fz_font *font)
 	pdf_obj *dfonts = NULL;
 	unsigned char digest[16];
 
-	fref = pdf_find_font_resource(ctx, doc, PDF_CID_FONT_RESOURCE, 0, font->buffer, digest);
+	fref = pdf_find_font_resource(ctx, doc, PDF_CID_FONT_RESOURCE, 0, font, digest);
 	if (fref)
 		return fref;
 
@@ -2087,7 +2087,7 @@ pdf_add_simple_font(fz_context *ctx, pdf_document *doc, fz_font *font, int encod
 	const char **enc;
 	unsigned char digest[16];
 
-	fref = pdf_find_font_resource(ctx, doc, PDF_SIMPLE_FONT_RESOURCE, encoding, font->buffer, digest);
+	fref = pdf_find_font_resource(ctx, doc, PDF_SIMPLE_FONT_RESOURCE, encoding, font, digest);
 	if (fref)
 		return fref;
 
@@ -2199,7 +2199,7 @@ pdf_add_cjk_font(fz_context *ctx, pdf_document *doc, fz_font *fzfont, int script
 	if (serif)
 		flags |= PDF_FD_SERIF;
 
-	fref = pdf_find_font_resource(ctx, doc, PDF_CJK_FONT_RESOURCE, script, fzfont->buffer, digest);
+	fref = pdf_find_font_resource(ctx, doc, PDF_CJK_FONT_RESOURCE, script, fzfont, digest);
 	if (fref)
 		return fref;
 
diff --git a/source/pdf/pdf-resources.c b/source/pdf/pdf-resources.c
index 55d6603e..82991f6e 100644
--- a/source/pdf/pdf-resources.c
+++ b/source/pdf/pdf-resources.c
@@ -109,24 +109,17 @@ pdf_insert_image_resource(fz_context *ctx, pdf_document *doc, unsigned char dige
  * it may be more problematic. */
 
 pdf_obj *
-pdf_find_font_resource(fz_context *ctx, pdf_document *doc, int type, int encoding, fz_buffer *item, unsigned char digest[16])
+pdf_find_font_resource(fz_context *ctx, pdf_document *doc, int type, int encoding, fz_font *item, unsigned char digest[16])
 {
-	fz_md5 state;
-	unsigned char *data;
-	size_t size;
 	pdf_obj *res;
 
 	if (!doc->resources.fonts)
 		doc->resources.fonts = fz_new_hash_table(ctx, 4096, 16, -1, pdf_drop_obj_as_void);
 
-	size = fz_buffer_storage(ctx, item, &data);
+	fz_font_digest(ctx, item, digest);
 
-	/* Create md5 and see if we have the item in our table */
-	fz_md5_init(&state);
-	fz_md5_update(&state, (unsigned char*)&type, sizeof type);
-	fz_md5_update(&state, (unsigned char*)&encoding, sizeof encoding);
-	fz_md5_update(&state, data, size);
-	fz_md5_final(&state, digest);
+	digest[0] += type;
+	digest[1] += encoding;
 
 	res = fz_hash_find(ctx, doc->resources.fonts, digest);
 	if (res)