rpm/ndbglue.diff

--- ./lib/backend/ndb/glue.c.orig
+++ ./lib/backend/ndb/glue.c
@@ -19,6 +19,8 @@ struct dbiCursor_s {
     const void *key;
     unsigned int keylen;
     unsigned int hdrNum;
+    void *data;
+    unsigned int datalen;
     int flags;
 
     unsigned int *list;
@@ -33,7 +35,7 @@ struct ndbEnv_s {
     int refs;
     int dofsync;
 
-    unsigned int hdrNum;
+    unsigned int hdrNum;		/* free for adoption */
     void *data;
     unsigned int datalen;
 };
@@ -278,6 +280,40 @@ static int ndb_Ctrl(rpmdb rdb, dbCtrlOp ctrl)
     return 0;
 }
 
+static void setenvdata(struct ndbEnv_s *ndbenv, unsigned int hdrNum, unsigned char *hdrBlob, unsigned int hdrLen)
+{
+    if (ndbenv->data)
+	free(ndbenv->data);
+    ndbenv->hdrNum = hdrNum;
+    ndbenv->data = hdrBlob;
+    ndbenv->datalen = hdrLen;
+}
+
+static void setdata(dbiCursor dbc, unsigned int hdrNum, unsigned char *hdrBlob, unsigned int hdrLen)
+{
+    struct ndbEnv_s *ndbenv = dbc->dbi->dbi_rpmdb->db_dbenv;
+    if (ndbenv->data)
+	setenvdata(ndbenv, 0, 0, 0);		/* clear dbenv cache */
+    if (dbc->data)
+	free(dbc->data);
+    dbc->hdrNum = hdrNum;
+    dbc->data = hdrBlob;
+    dbc->datalen = hdrLen;
+}
+
+static void adoptdata(dbiCursor dbc)
+{
+    struct ndbEnv_s *ndbenv = dbc->dbi->dbi_rpmdb->db_dbenv;
+    if (dbc->data)
+	free(dbc->data);
+    dbc->hdrNum = ndbenv->hdrNum;
+    dbc->data = ndbenv->data;
+    dbc->datalen = ndbenv->datalen;
+    ndbenv->hdrNum = 0;
+    ndbenv->data = 0;
+    ndbenv->datalen = 0;
+}
+
 static dbiCursor ndb_CursorInit(dbiIndex dbi, unsigned int flags)
 {
     dbiCursor dbc = xcalloc(1, sizeof(*dbc));
@@ -293,21 +329,17 @@ static dbiCursor ndb_CursorFree(dbiIndex dbi, dbiCursor dbc)
 	    free(dbc->list);
 	if (dbc->listdata)
 	    free(dbc->listdata);
+	if (dbc->data) {
+	    /* release data into dbenv so that the next cursor can adopt it */
+	    struct ndbEnv_s *ndbenv = dbc->dbi->dbi_rpmdb->db_dbenv;
+	    setenvdata(ndbenv, dbc->hdrNum, dbc->data, dbc->datalen);
+	}
 	free(dbc);
     }
     return NULL;
 }
 
 
-static void setdata(dbiCursor dbc,  unsigned int hdrNum, unsigned char *hdrBlob, unsigned int hdrLen)
-{
-    struct ndbEnv_s *ndbenv = dbc->dbi->dbi_rpmdb->db_dbenv;
-    if (ndbenv->data)
-	free(ndbenv->data);
-    ndbenv->hdrNum  = hdrNum;
-    ndbenv->data    = hdrBlob;
-    ndbenv->datalen = hdrLen;
-}
 
 static rpmRC ndb_pkgdbPut(dbiIndex dbi, dbiCursor dbc,  unsigned int *hdrNum, unsigned char *hdrBlob, unsigned int hdrLen)
 {
@@ -324,7 +356,6 @@ static rpmRC ndb_pkgdbPut(dbiIndex dbi, dbiCursor dbc,  unsigned int *hdrNum, un
 	rc = rpmpkgPut(dbc->dbi->dbi_db, hnum, hdrBlob, hdrLen);
 
     if (!rc) {
-	dbc->hdrNum = hnum;
 	setdata(dbc, hnum, 0, 0);
 	*hdrNum = hnum;
     }
@@ -333,7 +364,6 @@ static rpmRC ndb_pkgdbPut(dbiIndex dbi, dbiCursor dbc,  unsigned int *hdrNum, un
 
 static rpmRC ndb_pkgdbDel(dbiIndex dbi, dbiCursor dbc,  unsigned int hdrNum)
 {
-    dbc->hdrNum = 0;
     setdata(dbc, 0, 0, 0);
     return rpmpkgDel(dbc->dbi->dbi_db, hdrNum);
 }
@@ -362,7 +392,6 @@ static rpmRC ndb_pkgdbIter(dbiIndex dbi, dbiCursor dbc, unsigned char **hdrBlob,
 	    break;
 	dbc->ilist++;
 	if (!rc) {
-	    dbc->hdrNum = hdrNum;
 	    setdata(dbc, hdrNum, *hdrBlob, *hdrLen);
 	    break;
 	}
@@ -377,16 +406,16 @@ static rpmRC ndb_pkgdbGet(dbiIndex dbi, dbiCursor dbc, unsigned int hdrNum, unsi
 
     if (!hdrNum)
 	return ndb_pkgdbIter(dbi, dbc, hdrBlob, hdrLen);
-    if (hdrNum == ndbenv->hdrNum && ndbenv->data) {
-	*hdrBlob = ndbenv->data;
-	*hdrLen = ndbenv->datalen;
+    if (!dbc->data && ndbenv->data)
+	adoptdata(dbc);
+    if (dbc->data && hdrNum == dbc->hdrNum) {
+	*hdrBlob = dbc->data;
+	*hdrLen = dbc->datalen;
 	return RPMRC_OK;
     }
     rc = rpmpkgGet(dbc->dbi->dbi_db, hdrNum, hdrBlob, hdrLen);
-    if (!rc) {
-	dbc->hdrNum = hdrNum;
+    if (!rc)
 	setdata(dbc, hdrNum, *hdrBlob, *hdrLen);
-    }
     return rc;
 }