From 0224ad402d353e9584b7355d54dee240500ee2ac Mon Sep 17 00:00:00 2001
From: Vreixo Formoso Lopes <metalpain2002@yahoo.es>
Date: Wed, 3 Oct 2007 16:32:09 +0000
Subject: [PATCH] Some fixes in burn_source implementation

---
 libisofs/ecma119.c | 52 +++++++++++++++++++++++++++++++++++-----------
 libisofs/ecma119.h | 11 ++++------
 2 files changed, 44 insertions(+), 19 deletions(-)

diff --git a/libisofs/ecma119.c b/libisofs/ecma119.c
index dcbc698..1e9c07e 100644
--- a/libisofs/ecma119.c
+++ b/libisofs/ecma119.c
@@ -479,6 +479,7 @@ ecma119_target_new(struct iso_volset *volset,
 	/* prepare for writing */
 	t->curblock = 0;
 	t->state = ECMA119_WRITE_SYSTEM_AREA;
+	t->bytes_read = 2048;
 
 	return t;
 }
@@ -863,30 +864,57 @@ write_data_chunk(struct ecma119_write_target *t, uint8_t *buf)
 }
 
 static int
-bs_read(struct burn_source *bs, unsigned char *buf, int size)
+bs_read_block(struct burn_source *bs)
 {
 	struct ecma119_write_target *t = (struct ecma119_write_target*)bs->data;
 	
-	if (size != t->block_size) {
-		printf("[ERROR] You can only read in %d chunks\n", t->block_size);
-		return -1;
-	}
-	
 	if (t->curblock >= t->vol_space_size) {
 		/* total_size could be setted by libburn */
-		if ( t->curblock >= (t->total_size / (off_t) t->block_size) ) {
+		if ( t->curblock < (t->total_size / (off_t) t->block_size) ) {
 			/* we pad the image */
-			memset(buf, 0, size);
-			return size;
+			memset(t->buffer, 0, t->block_size);
+			t->curblock++;
+			return t->block_size;
 		}
 		return -1;
 	}
 	if (t->state_data_valid)
-		write_data_chunk(t, buf);
+		write_data_chunk(t, t->buffer);
 	else
-		writers[t->state](t, buf);
+		writers[t->state](t, t->buffer);
 	t->curblock++;
-	return size;
+	return t->block_size;
+}
+
+static int
+bs_read(struct burn_source *bs, unsigned char *buf, int size)
+{
+	int ret = 0,summed_ret = 0;
+	struct ecma119_write_target *t = (struct ecma119_write_target*)bs->data;
+
+        /* make safe against partial buffer returns */
+        while (1) {
+		if (t->bytes_read == 2048) {
+			/* we need to read next block */
+			t->bytes_read = 0;
+			ret = bs_read_block(bs);
+			if (ret < 0)
+				return -1;
+		}
+
+		int bytes_to_read = 2048 - t->bytes_read;
+		if (summed_ret + bytes_to_read > size) {
+			bytes_to_read = size - summed_ret;
+		}
+
+		memcpy(buf + summed_ret, t->buffer, bytes_to_read);
+
+		t->bytes_read += bytes_to_read;
+                summed_ret += bytes_to_read;
+                if (summed_ret >= size)
+	        	break;
+        }
+        return summed_ret;
 }
 
 static off_t
diff --git a/libisofs/ecma119.h b/libisofs/ecma119.h
index bdc67a4..0743bcd 100644
--- a/libisofs/ecma119.h
+++ b/libisofs/ecma119.h
@@ -174,17 +174,14 @@ struct ecma119_write_target
 
 	/* for writing out files */
 	struct state_files {
-//		off_t pos;	/* The number of bytes we have written
-//				 * so far in the current file.
-//				 */
-//		off_t data_len;/* The number of bytes in the currently
-//				 * open file.
-//				 */
-//		FILE *fd;	/* The currently open file. */
 		struct iso_file_src *src; /* source for reading from the file */
 		int file;	/* The index in filelist that we are
 				 * currently writing (or about to write). */
 	} state_files;
+
+	/* temp buffer for read functions */
+	uint8_t buffer[2048];
+	int bytes_read;
 };
 
 #define BP(a,b) [(b) - (a) + 1]