libalpm: remove from_md5 and to_md5 from pmdelta_t

The from_md5 and to_md5 fields were a nice extra safety, which would avoid
trying to apply deltas on corrupted package files. However, they are not
strictly necessary, since xdelta should be able to detect that on its own.

The main problem is that it is impossible to compute these informations from
the delta only. So repo-add would not be able to compute the delta entry
based on just the delta file.

Signed-off-by: Xavier Chantry <shiningxc@gmail.com>
Signed-off-by: Dan McGee <dan@archlinux.org>

4 files changed, 20 insertions, 54 deletions

diff --git a/lib/libalpm/alpm.h b/lib/libalpm/alpm.h
index 3836d608..43df31c1 100644
--- a/lib/libalpm/alpm.h
+++ b/lib/libalpm/alpm.h
@@ -229,9 +229,7 @@ off_t alpm_pkg_download_size(pmpkg_t *newpkg);
  */
 
 const char *alpm_delta_get_from(pmdelta_t *delta);
-const char *alpm_delta_get_from_md5sum(pmdelta_t *delta);
 const char *alpm_delta_get_to(pmdelta_t *delta);
-const char *alpm_delta_get_to_md5sum(pmdelta_t *delta);
 const char *alpm_delta_get_filename(pmdelta_t *delta);
 const char *alpm_delta_get_md5sum(pmdelta_t *delta);
 off_t alpm_delta_get_size(pmdelta_t *delta);
diff --git a/lib/libalpm/delta.c b/lib/libalpm/delta.c
index ff77501e..9e4bcb42 100644
--- a/lib/libalpm/delta.c
+++ b/lib/libalpm/delta.c
@@ -43,24 +43,12 @@ const char SYMEXPORT *alpm_delta_get_from(pmdelta_t *delta)
 	return(delta->from);
 }
 
-const char SYMEXPORT *alpm_delta_get_from_md5sum(pmdelta_t *delta)
-{
-	ASSERT(delta != NULL, return(NULL));
-	return(delta->from_md5);
-}
-
 const char SYMEXPORT *alpm_delta_get_to(pmdelta_t *delta)
 {
 	ASSERT(delta != NULL, return(NULL));
 	return(delta->to);
 }
 
-const char SYMEXPORT *alpm_delta_get_to_md5sum(pmdelta_t *delta)
-{
-	ASSERT(delta != NULL, return(NULL));
-	return(delta->to_md5);
-}
-
 const char SYMEXPORT *alpm_delta_get_filename(pmdelta_t *delta)
 {
 	ASSERT(delta != NULL, return(NULL));
@@ -104,12 +92,10 @@ static alpm_list_t *delta_graph_init(alpm_list_t *deltas)
 
 		/* determine whether a base 'from' file exists */
 		fpath = _alpm_filecache_find(vdelta->from);
-		md5sum = alpm_compute_md5sum(fpath);
-		if(fpath && md5sum && strcmp(md5sum, vdelta->from_md5) == 0) {
+		if(fpath) {
 			v->weight = vdelta->download_size;
 		}
 		FREE(fpath);
-		FREE(md5sum);
 
 		v->data = vdelta;
 		vertices = alpm_list_add(vertices, v);
@@ -131,8 +117,7 @@ static alpm_list_t *delta_graph_init(alpm_list_t *deltas)
 			 *     3_to_4
 			 * If J 'from' is equal to I 'to', then J is a child of I.
 			 * */
-			if(strcmp(d_j->from, d_i->to) == 0
-					&& strcmp(d_j->from_md5, d_i->to_md5) == 0) {
+			if(strcmp(d_j->from, d_i->to) == 0) {
 				v_i->children = alpm_list_add(v_i->children, v_j);
 			}
 		}
@@ -142,7 +127,7 @@ static alpm_list_t *delta_graph_init(alpm_list_t *deltas)
 }
 
 static off_t delta_vert(alpm_list_t *vertices,
-		const char *to, const char *to_md5, alpm_list_t **path) {
+		const char *to, alpm_list_t **path) {
 	alpm_list_t *i;
 	pmgraph_t *v;
 	while(1) {
@@ -186,8 +171,7 @@ static off_t delta_vert(alpm_list_t *vertices,
 		pmgraph_t *v_i = i->data;
 		pmdelta_t *d_i = v_i->data;
 
-		if(strcmp(d_i->to, to) == 0
-				|| strcmp(d_i->to_md5, to_md5) == 0) {
+		if(strcmp(d_i->to, to) == 0) {
 			if(v == NULL || v_i->weight < v->weight) {
 				v = v_i;
 				bestsize = v->weight;
@@ -212,14 +196,13 @@ static off_t delta_vert(alpm_list_t *vertices,
  * size, not the length of the path.
  * @param deltas the list of pmdelta_t * objects that a file has
  * @param to the file to start the search at
- * @param to_md5 the md5sum of the above named file
  * @param path the pointer to a list location where pmdelta_t * objects that
  * have the smallest size are placed. NULL is set if there is no path
  * possible with the files available.
  * @return the size of the path stored, or LONG_MAX if path is unfindable
  */
 off_t _alpm_shortest_delta_path(alpm_list_t *deltas,
-		const char *to, const char *to_md5, alpm_list_t **path)
+		const char *to, alpm_list_t **path)
 {
 	alpm_list_t *bestpath = NULL;
 	alpm_list_t *vertices;
@@ -236,7 +219,7 @@ off_t _alpm_shortest_delta_path(alpm_list_t *deltas,
 
 	vertices = delta_graph_init(deltas);
 
-	bestsize = delta_vert(vertices, to, to_md5, &bestpath);
+	bestsize = delta_vert(vertices, to, &bestpath);
 
 	_alpm_log(PM_LOG_DEBUG, "delta shortest-path search complete\n");
 
@@ -250,7 +233,7 @@ off_t _alpm_shortest_delta_path(alpm_list_t *deltas,
 /** Parses the string representation of a pmdelta_t object.
  * This function assumes that the string is in the correct format.
  * This format is as follows:
- * $oldfile $oldmd5 $newfile $newmd5 $deltafile $deltamd5 $deltasize
+ * $deltafile $deltamd5 $deltasize $oldfile $newfile
  * @param line the string to parse
  * @return A pointer to the new pmdelta_t object
  */
@@ -262,9 +245,8 @@ pmdelta_t *_alpm_delta_parse(char *line)
 	regex_t reg;
 
 	regcomp(&reg,
-			"^[^[:space:]]* [[:xdigit:]]{32}"
-			" [^[:space:]]* [[:xdigit:]]{32}"
-			" [^[:space:]]* [[:xdigit:]]{32} [[:digit:]]*$",
+			"^[^[:space:]]* [[:xdigit:]]{32} [[:digit:]]*"
+			" [^[:space:]]* [^[:space:]]*$",
 			REG_EXTENDED | REG_NOSUB | REG_NEWLINE);
 	if(regexec(&reg, line, 0, 0, 0) != 0) {
 		/* delta line is invalid, return NULL */
@@ -278,34 +260,27 @@ pmdelta_t *_alpm_delta_parse(char *line)
 	tmp2 = tmp;
 	tmp = strchr(tmp, ' ');
 	*(tmp++) = '\0';
-	STRDUP(delta->from, tmp2, RET_ERR(PM_ERR_MEMORY, NULL));
-
-	tmp2 = tmp;
-	tmp = strchr(tmp, ' ');
-	*(tmp++) = '\0';
-	STRDUP(delta->from_md5, tmp2, RET_ERR(PM_ERR_MEMORY, NULL));
+	STRDUP(delta->delta, tmp2, RET_ERR(PM_ERR_MEMORY, NULL));
 
 	tmp2 = tmp;
 	tmp = strchr(tmp, ' ');
 	*(tmp++) = '\0';
-	STRDUP(delta->to, tmp2, RET_ERR(PM_ERR_MEMORY, NULL));
+	STRDUP(delta->delta_md5, tmp2, RET_ERR(PM_ERR_MEMORY, NULL));
 
 	tmp2 = tmp;
 	tmp = strchr(tmp, ' ');
 	*(tmp++) = '\0';
-	STRDUP(delta->to_md5, tmp2, RET_ERR(PM_ERR_MEMORY, NULL));
+	delta->delta_size = atol(tmp2);
 
 	tmp2 = tmp;
 	tmp = strchr(tmp, ' ');
 	*(tmp++) = '\0';
-	STRDUP(delta->delta, tmp2, RET_ERR(PM_ERR_MEMORY, NULL));
+	STRDUP(delta->from, tmp2, RET_ERR(PM_ERR_MEMORY, NULL));
 
 	tmp2 = tmp;
-	tmp = strchr(tmp, ' ');
-	*(tmp++) = '\0';
-	STRDUP(delta->delta_md5, tmp2, RET_ERR(PM_ERR_MEMORY, NULL));
+	STRDUP(delta->to, tmp2, RET_ERR(PM_ERR_MEMORY, NULL));
 
-	delta->delta_size = atol(tmp);
+	_alpm_log(PM_LOG_DEBUG, "delta : %s %s '%lld'\n", delta->from, delta->to, (long long)delta->delta_size);
 
 	return(delta);
 }
@@ -313,9 +288,7 @@ pmdelta_t *_alpm_delta_parse(char *line)
 void _alpm_delta_free(pmdelta_t *delta)
 {
 	FREE(delta->from);
-	FREE(delta->from_md5);
 	FREE(delta->to);
-	FREE(delta->to_md5);
 	FREE(delta->delta);
 	FREE(delta->delta_md5);
 	FREE(delta);
diff --git a/lib/libalpm/delta.h b/lib/libalpm/delta.h
index 5bb86b94..29a2b0c9 100644
--- a/lib/libalpm/delta.h
+++ b/lib/libalpm/delta.h
@@ -24,20 +24,16 @@
 #include "alpm.h"
 
 struct __pmdelta_t {
-	/** filename of the 'before' file */
-	char *from;
-	/** md5sum of the 'before' file */
-	char *from_md5;
-	/** filename of the 'after' file */
-	char *to;
-	/** md5sum of the 'after' file */
-	char *to_md5;
 	/** filename of the delta patch */
 	char *delta;
 	/** md5sum of the delta file */
 	char *delta_md5;
 	/** filesize of the delta file */
 	off_t delta_size;
+	/** filename of the 'before' file */
+	char *from;
+	/** filename of the 'after' file */
+	char *to;
 	/** download filesize of the delta file */
 	off_t download_size;
 };
@@ -45,7 +41,7 @@ struct __pmdelta_t {
 pmdelta_t *_alpm_delta_parse(char *line);
 void _alpm_delta_free(pmdelta_t *delta);
 off_t _alpm_shortest_delta_path(alpm_list_t *deltas,
-		const char *to, const char *to_md5, alpm_list_t **path);
+		const char *to, alpm_list_t **path);
 
 #endif /* _ALPM_DELTA_H */
 
diff --git a/lib/libalpm/sync.c b/lib/libalpm/sync.c
index 709a36dc..fca96d8f 100644
--- a/lib/libalpm/sync.c
+++ b/lib/libalpm/sync.c
@@ -372,7 +372,6 @@ static int compute_download_size(pmpkg_t *newpkg)
 		dltsize = _alpm_shortest_delta_path(
 			alpm_pkg_get_deltas(newpkg),
 			alpm_pkg_get_filename(newpkg),
-			alpm_pkg_get_md5sum(newpkg),
 			&newpkg->delta_path);
 
 		if(newpkg->delta_path && (dltsize < pkgsize * MAX_DELTA_RATIO)) {