Simplify PDF resource caching table handling.

1 files changed, 50 insertions, 114 deletions

diff --git a/source/pdf/pdf-resources.c b/source/pdf/pdf-resources.c
index 9b539fa9..0772d3a4 100644
--- a/source/pdf/pdf-resources.c
+++ b/source/pdf/pdf-resources.c
@@ -1,29 +1,7 @@
 #include "mupdf/pdf.h"
 
 static void
-res_table_free(fz_context *ctx, pdf_res_table *table)
-{
-	int i, n;
-	pdf_obj *res;
-
-	if (table == NULL)
-		return;
-	if (table->hash != NULL)
-	{
-		n = fz_hash_len(ctx, table->hash);
-		for (i = 0; i < n; i++)
-		{
-			res = fz_hash_get_val(ctx, table->hash, i);
-			if (res)
-				pdf_drop_obj(ctx, res);
-		}
-		fz_drop_hash(ctx, table->hash);
-	}
-	fz_free(ctx, table);
-}
-
-static void
-res_image_get_md5(fz_context *ctx, fz_image *image, unsigned char *digest)
+fz_md5_image(fz_context *ctx, fz_image *image, unsigned char digest[16])
 {
 	fz_pixmap *pixmap;
 	fz_md5 state;
@@ -45,7 +23,7 @@ res_image_get_md5(fz_context *ctx, fz_image *image, unsigned char *digest)
 
 /* Image specific methods */
 static void
-res_image_init(fz_context *ctx, pdf_document *doc, pdf_res_table *table)
+pdf_preload_image_resources(fz_context *ctx, pdf_document *doc)
 {
 	int len, k;
 	pdf_obj *obj;
@@ -60,7 +38,6 @@ res_image_init(fz_context *ctx, pdf_document *doc, pdf_res_table *table)
 
 	fz_try(ctx)
 	{
-		table->hash = fz_new_hash_table(ctx, 4096, 16, -1);
 		len = pdf_count_objects(ctx, doc);
 		for (k = 1; k < len; k++)
 		{
@@ -69,18 +46,15 @@ res_image_init(fz_context *ctx, pdf_document *doc, pdf_res_table *table)
 			if (pdf_name_eq(ctx, type, PDF_NAME_Image))
 			{
 				image = pdf_load_image(ctx, doc, obj);
-				res_image_get_md5(ctx, image, digest);
+				fz_md5_image(ctx, image, digest);
 				fz_drop_image(ctx, image);
 				image = NULL;
 
 				/* Don't allow overwrites. */
-				if (fz_hash_find(ctx, table->hash, digest) == NULL)
-					fz_hash_insert(ctx, table->hash, digest, obj);
-			}
-			else
-			{
-				pdf_drop_obj(ctx, obj);
+				if (!fz_hash_find(ctx, doc->resources.images, digest))
+					fz_hash_insert(ctx, doc->resources.images, digest, pdf_keep_obj(ctx, obj));
 			}
+			pdf_drop_obj(ctx, obj);
 			obj = NULL;
 		}
 	}
@@ -91,126 +65,88 @@ res_image_init(fz_context *ctx, pdf_document *doc, pdf_res_table *table)
 	}
 	fz_catch(ctx)
 	{
-		res_table_free(ctx, table);
 		fz_rethrow(ctx);
 	}
 }
 
-static pdf_obj *
-res_image_search(fz_context *ctx, pdf_document *doc, pdf_res_table *table, void *item, unsigned char *digest)
+pdf_obj *
+pdf_find_image_resource(fz_context *ctx, pdf_document *doc, fz_image *item, unsigned char digest[16])
 {
-	fz_image *image = item;
-	fz_hash_table *hash = table->hash;
 	pdf_obj *res;
 
-	if (hash == NULL)
-		res_image_init(ctx, doc, doc->resources->image);
-	hash = doc->resources->image->hash;
+	if (!doc->resources.images)
+	{
+		doc->resources.images = fz_new_hash_table(ctx, 4096, 16, -1);
+		pdf_preload_image_resources(ctx, doc);
+	}
 
 	/* Create md5 and see if we have the item in our table */
-	res_image_get_md5(ctx, image, digest);
-	res = fz_hash_find(ctx, hash, digest);
+	fz_md5_image(ctx, item, digest);
+	res = fz_hash_find(ctx, doc->resources.images, digest);
 	if (res)
 		pdf_keep_obj(ctx, res);
 	return res;
 }
 
-/* Font specific methods */
-
-/* We do need to come up with an effective way to see what is already in the
- * file to avoid adding to what is already there. This is avoided for pdfwrite
- * as we check as we add each font.  For adding text to an existing file though
- * it may be more problematic */
-static void
-res_font_init(fz_context *ctx, pdf_document *doc, pdf_res_table *table)
+pdf_obj *
+pdf_insert_image_resource(fz_context *ctx, pdf_document *doc, unsigned char digest[15], pdf_obj *obj)
 {
-	table->hash = fz_new_hash_table(ctx, 4096, 16, -1);
+	pdf_obj *res = fz_hash_insert(ctx, doc->resources.images, digest, obj);
+	if (res)
+		fz_warn(ctx, "warning: image resource already present");
+	else
+		res = pdf_keep_obj(ctx, obj);
+	return res;
 }
 
-static void
-res_font_get_md5(fz_context *ctx, fz_buffer *buffer, unsigned char *digest)
-{
-	fz_md5 state;
-
-	fz_md5_init(&state);
-	fz_md5_update(&state, buffer->data, buffer->len);
-	fz_md5_final(&state, digest);
-}
+/* We do need to come up with an effective way to see what is already in the
+ * file to avoid adding to what is already there. This is avoided for pdfwrite
+ * as we check as we add each font. For adding text to an existing file though
+ * it may be more problematic. */
 
-static pdf_obj *
-res_font_search(fz_context *ctx, pdf_document *doc, pdf_res_table *table, void *item, unsigned char digest[16])
+pdf_obj *
+pdf_find_font_resource(fz_context *ctx, pdf_document *doc, fz_buffer *item, unsigned char digest[16])
 {
-	fz_buffer *buffer = item;
-	fz_hash_table *hash = table->hash;
 	pdf_obj *res;
 
-	if (hash == NULL)
-		res_font_init(ctx, doc, doc->resources->font);
-	hash = doc->resources->font->hash;
+	if (!doc->resources.fonts)
+		doc->resources.fonts = fz_new_hash_table(ctx, 4096, 16, -1);
 
 	/* Create md5 and see if we have the item in our table */
-	res_font_get_md5(ctx, buffer, digest);
-	res = fz_hash_find(ctx, hash, digest);
+	fz_md5_buffer(ctx, item, digest);
+	res = fz_hash_find(ctx, doc->resources.fonts, digest);
 	if (res)
 		pdf_keep_obj(ctx, res);
 	return res;
 }
 
-/* Accessible methods */
 pdf_obj *
-pdf_find_resource(fz_context *ctx, pdf_document *doc, pdf_res_table *table, void *item, unsigned char md5[16])
+pdf_insert_font_resource(fz_context *ctx, pdf_document *doc, unsigned char digest[15], pdf_obj *obj)
 {
-	return table->search(ctx, doc, table, item, md5);
+	pdf_obj *res = fz_hash_insert(ctx, doc->resources.fonts, digest, obj);
+	if (res)
+		fz_warn(ctx, "warning: font resource already present");
+	else
+		res = pdf_keep_obj(ctx, obj);
+	return res;
 }
 
-pdf_obj *
-pdf_insert_resource(fz_context *ctx, pdf_res_table *table, void *key, pdf_obj *obj)
+static void
+res_table_free(fz_context *ctx, fz_hash_table *hash)
 {
-	pdf_obj *res;
-
-	fz_try(ctx)
-	{
-		res = fz_hash_insert(ctx, table->hash, key, obj);
-		if (res != NULL)
-			fz_warn(ctx, "warning: resource already present");
-		else
-			res = pdf_keep_obj(ctx, obj);
-	}
-	fz_catch(ctx)
+	int i, n;
+	if (hash)
 	{
-		fz_rethrow(ctx);
+		n = fz_hash_len(ctx, hash);
+		for (i = 0; i < n; i++)
+			pdf_drop_obj(ctx, fz_hash_get_val(ctx, hash, i));
+		fz_drop_hash(ctx, hash);
 	}
-	return res;
 }
 
 void
 pdf_drop_resource_tables(fz_context *ctx, pdf_document *doc)
 {
-	if (doc->resources == NULL)
-		return;
-	res_table_free(ctx, doc->resources->color);
-	res_table_free(ctx, doc->resources->font);
-	res_table_free(ctx, doc->resources->image);
-	res_table_free(ctx, doc->resources->pattern);
-	res_table_free(ctx, doc->resources->shading);
-	fz_free(ctx, doc->resources);
-	doc->resources = NULL;
-}
-
-void
-pdf_init_resource_tables(fz_context *ctx, pdf_document *doc)
-{
-	fz_try(ctx)
-	{
-		doc->resources = fz_malloc_struct(ctx, pdf_resource_tables);
-		doc->resources->image = fz_malloc_struct(ctx, pdf_res_table);
-		doc->resources->image->search = res_image_search;
-		doc->resources->font = fz_malloc_struct(ctx, pdf_res_table);
-		doc->resources->font->search = res_font_search;
-	}
-	fz_catch(ctx)
-	{
-		pdf_drop_resource_tables(ctx, doc);
-		fz_rethrow(ctx);
-	}
+	res_table_free(ctx, doc->resources.fonts);
+	res_table_free(ctx, doc->resources.images);
 }