From: Kamen Mazdrashki <kamenim@samba.org>
Date: Fri, 9 Jul 2010 16:27:13 +0000 (+0300)
Subject: s4-ldb: Implement ldb_msg_diff_ex() function to accept a memory context from client
X-Git-Url: http://git.samba.org/?p=kamenim%2Fsamba.git;a=commitdiff_plain;h=35a3455f1a0062d77ba7e03d4da2bd6eab7bb040

s4-ldb: Implement ldb_msg_diff_ex() function to accept a memory context from client

This function does what ldb_msg_diff() function should do,
but the interface is little bit changed to accept memory context
from caller.
---

diff --git a/source4/lib/ldb/common/ldb_msg.c b/source4/lib/ldb/common/ldb_msg.c
index 4d0149af8f..e54caa8811 100644
--- a/source4/lib/ldb/common/ldb_msg.c
+++ b/source4/lib/ldb/common/ldb_msg.c
@@ -642,6 +642,98 @@ struct ldb_message *ldb_msg_diff(struct ldb_context *ldb,
 	return mod;
 }
 
+/**
+ * return a ldb_message representing the differences between msg1 and msg2.
+ * If you then use this in a ldb_modify() call it can be used to save edits to a message
+ *
+ * Result message is constructed as follows:
+ * - LDB_FLAG_MOD_ADD     - elements found only in msg2
+ * - LDB_FLAG_MOD_REPLACE - elements in msg2 that have different value in msg1
+ *                          Value for msg2 element is used
+ * - LDB_FLAG_MOD_DELETE  - elements found only in msg2
+ *
+ * @return LDB_SUCCESS or LDB_ERR_OPERATIONS_ERROR
+ */
+int ldb_msg_diff_ex(struct ldb_context *ldb,
+		    struct ldb_message *msg1,
+		    struct ldb_message *msg2,
+		    TALLOC_CTX *mem_ctx,
+		    struct ldb_message **_msg_out)
+{
+	int ldb_res;
+	unsigned int i;
+	struct ldb_message *mod;
+	struct ldb_message_element *el;
+	TALLOC_CTX *temp_ctx;
+
+	temp_ctx = talloc_new(mem_ctx);
+	if (!temp_ctx) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	mod = ldb_msg_new(temp_ctx);
+	if (mod == NULL) {
+		goto failed;
+	}
+
+	mod->dn = msg1->dn;
+	mod->num_elements = 0;
+	mod->elements = NULL;
+
+	/* canonicalize msg2 so we have no
+	 * repeated elements */
+	msg2 = ldb_msg_canonicalize(ldb, msg2);
+	if (msg2 == NULL) {
+		goto failed;
+	}
+
+	/* steal msg2 into mod context as it is
+	 * allocated in ldb's context */
+	talloc_steal(mod, msg2);
+
+	/* look in msg2 to find elements that need to be added
+	   or modified */
+	for (i=0;i<msg2->num_elements;i++) {
+		el = ldb_msg_find_element(msg1, msg2->elements[i].name);
+
+		if (el && ldb_msg_element_compare(el, &msg2->elements[i]) == 0) {
+			continue;
+		}
+
+		ldb_res = ldb_msg_add(mod,
+		                      &msg2->elements[i],
+		                      el ? LDB_FLAG_MOD_REPLACE : LDB_FLAG_MOD_ADD);
+		if (ldb_res != LDB_SUCCESS) {
+			goto failed;
+		}
+	}
+
+	/* look in msg1 to find elements that need to be deleted */
+	for (i=0;i<msg1->num_elements;i++) {
+		el = ldb_msg_find_element(msg2, msg1->elements[i].name);
+		if (el == NULL) {
+			ldb_res = ldb_msg_add_empty(mod,
+			                            msg1->elements[i].name,
+			                            LDB_FLAG_MOD_DELETE, NULL);
+			if (ldb_res != LDB_SUCCESS) {
+				goto failed;
+			}
+		}
+	}
+
+	/* steal resulting message into supplied context */
+	talloc_steal(mem_ctx, mod);
+	*_msg_out = mod;
+
+	talloc_free(temp_ctx);
+	return LDB_SUCCESS;
+
+failed:
+	talloc_free(temp_ctx);
+	return LDB_ERR_OPERATIONS_ERROR;
+}
+
+
 int ldb_msg_sanity_check(struct ldb_context *ldb, 
 			 const struct ldb_message *msg)
 {
diff --git a/source4/lib/ldb/include/ldb.h b/source4/lib/ldb/include/ldb.h
index 039f70895a..f2362c5394 100644
--- a/source4/lib/ldb/include/ldb.h
+++ b/source4/lib/ldb/include/ldb.h
@@ -1859,6 +1859,24 @@ struct ldb_message *ldb_msg_diff(struct ldb_context *ldb,
 				 struct ldb_message *msg1,
 				 struct ldb_message *msg2);
 
+/**
+ * return a ldb_message representing the differences between msg1 and msg2.
+ * If you then use this in a ldb_modify() call it can be used to save edits to a message
+ *
+ * Result message is constructed as follows:
+ * - LDB_FLAG_MOD_ADD     - elements found only in msg2
+ * - LDB_FLAG_MOD_REPLACE - elements in msg2 that have different value in msg1
+ *                          Value for msg2 element is used
+ * - LDB_FLAG_MOD_DELETE  - elements found only in msg2
+ *
+ * @return LDB_SUCCESS or LDB_ERR_OPERATIONS_ERROR
+ */
+int ldb_msg_diff_ex(struct ldb_context *ldb,
+		    struct ldb_message *msg1,
+		    struct ldb_message *msg2,
+		    TALLOC_CTX *mem_ctx,
+		    struct ldb_message **_msg_out);
+
 /**
    Tries to find a certain string attribute in a message