allow to load the same alias multiple times (unless dbRecordsOnceOnly…

… is set)
dirk-zimoch · Aug 23, 2024 · 5bedf2f · 5bedf2f
1 parent 052a0c7
commit 5bedf2f
Show file tree

Hide file tree

Showing 9 changed files with 83 additions and 17 deletions.
diff --git a/documentation/RELEASE_NOTES.md b/documentation/RELEASE_NOTES.md
@@ -22,6 +22,13 @@ should also be read to understand what has changed since earlier releases:
 
 ## Changes made on the 7.0 branch since 7.0.8.1
 
+### Allow to load the same alias multiple times
+
+Aliases can now be defined multiple times as long as they still refer to the
+same record, unless the shell variable dbRecordsOnceOnly is set.
+This allows to load database files multiple times, even if they contain
+alias definitions.
+
 ### Allow users to delete previously created records from the database
 
 From this release, record instances and aliases that have already been loaded

diff --git a/modules/database/src/ioc/dbStatic/dbLexRoutines.c b/modules/database/src/ioc/dbStatic/dbLexRoutines.c
@@ -1263,24 +1263,50 @@ static void dbRecordInfo(char *name, char *value)
     }
 }
 
+static long createAlias(DBENTRY *pdbentry, const char *alias)
+{
+    DBENTRY tempEntry;
+    long status;
+    dbRecordNode *precnode = pdbentry->precnode;
+
+    if (precnode->aliasedRecnode) precnode = precnode->aliasedRecnode;
+    dbInitEntry(pdbentry->pdbbase, &tempEntry);
+    status = dbFindRecord(&tempEntry, alias);
+    if (status == 0) {
+        if (tempEntry.precnode->aliasedRecnode != precnode) {
+            if (tempEntry.precnode->aliasedRecnode)
+                fprintf(stderr, ERL_ERROR ": Alias \"%s\" for \"%s\": name already used by an alias for \"%s\"\n",
+                            alias, dbGetRecordName(pdbentry),
+                            tempEntry.precnode->aliasedRecnode->recordname);
+            else
+                fprintf(stderr, ERL_ERROR ": Alias \"%s\" for \"%s\": name already used by a record\n",
+                            alias, dbGetRecordName(pdbentry));
+            status = S_dbLib_recExists;
+        } else if (dbRecordsOnceOnly) {
+            fprintf(stderr, ERL_ERROR ": Alias \"%s\" already defined and dbRecordsOnceOnly set.\n",
+                alias);
+            status = S_dbLib_recExists;
+        }
+    } else {
+        status = dbCreateAlias(pdbentry, alias);
+    }
+    dbFinishEntry(&tempEntry);
+    return status;
+}
+
 static void dbRecordAlias(char *name)
 {
     DBENTRY *pdbentry;
     tempListNode *ptempListNode;
-    long status;
-
     if(dbRecordNameValidate(name))
         return;
 
     if (duplicate) return;
     ptempListNode = (tempListNode *)ellFirst(&tempList);
     pdbentry = ptempListNode->item;
-    status = dbCreateAlias(pdbentry, name);
-    if (status) {
-        fprintf(stderr, "Can't create alias \"%s\" for \"%s\"\n",
-                    name, dbGetRecordName(pdbentry));
+
+    if (createAlias(pdbentry, name) != 0) {
         yyerror(NULL);
-        return;
     }
 }
 
@@ -1298,9 +1324,7 @@ static void dbAlias(char *name, char *alias)
                     alias, name);
         yyerror(NULL);
     }
-    else if (dbCreateAlias(pdbEntry, alias)) {
-        fprintf(stderr, "Can't create alias \"%s\" referring to \"%s\"\n",
-                    alias, name);
+    else if (createAlias(pdbEntry, alias) != 0) {
         yyerror(NULL);
     }
     dbFinishEntry(pdbEntry);

diff --git a/modules/database/test/ioc/db/Makefile b/modules/database/test/ioc/db/Makefile
@@ -183,6 +183,11 @@ testHarness_SRCS += dbStaticTest.c
 TESTFILES += ../dbStaticTest.db
 TESTFILES += ../dbStaticTestAlias1.db
 TESTFILES += ../dbStaticTestAlias2.db
+TESTFILES += ../dbStaticTestAliasAgain1.db
+TESTFILES += ../dbStaticTestAliasAgain2.db
+TESTFILES += ../dbStaticTestAliasAgain3.db
+TESTFILES += ../dbStaticTestAliasAgainError1.db
+TESTFILES += ../dbStaticTestAliasAgainError1.db
 TESTFILES += ../dbStaticTestRemove.db
 TESTS += dbStaticTest
 

diff --git a/modules/database/test/ioc/db/dbStaticTest.c b/modules/database/test/ioc/db/dbStaticTest.c
@@ -321,27 +321,32 @@ static void testDbVerify(const char *record)
     dbFinishEntry(&entry);
 }
 
-static void testWrongAliasRecord(const char *filename)
+static void testReadDatabase(const char *filename, int expectToFail)
 {
     FILE *fp = NULL;
+    long status;
     dbPath(pdbbase,"." OSI_PATH_LIST_SEPARATOR "..");
     dbOpenFile(pdbbase, filename, &fp);
     if(!fp) {
-        testAbort("Unable to read %s", filename);
+        testAbort("Unable to open %s", filename);
     }
-    testOk(dbReadDatabaseFP(&pdbbase, fp, NULL, NULL) != 0,
-           "Wrong alias record in %s is expected to fail", filename);
+    status = dbReadDatabaseFP(&pdbbase, fp, NULL, NULL);
+    testOk(!status == !expectToFail,
+            "Reading %s%s", filename,
+            expectToFail ? " is expected to fail" : "");
 }
 
 void dbTestIoc_registerRecordDeviceDriver(struct dbBase *);
 
+extern int dbRecordsOnceOnly;
+
 MAIN(dbStaticTest)
 {
     const char *ldir;
     char *ldirDup;
     FILE *fp = NULL;
 
-    testPlan(340);
+    testPlan(350);
     testdbPrepare();
 
     testdbReadDatabase("dbTestIoc.dbd", NULL, NULL);
@@ -370,8 +375,21 @@ MAIN(dbStaticTest)
     }
     free(ldirDup);
 
-    testWrongAliasRecord("dbStaticTestAlias1.db");
-    testWrongAliasRecord("dbStaticTestAlias2.db");
+    testReadDatabase("dbStaticTestAlias1.db", 1);
+    testReadDatabase("dbStaticTestAlias2.db", 1);
+
+    /* Test re-defining aliases */
+    testReadDatabase("dbStaticTestAliasAgain1.db", 0);
+    testReadDatabase("dbStaticTestAliasAgain1.db", 0);
+    testReadDatabase("dbStaticTestAliasAgain2.db", 0);
+    testReadDatabase("dbStaticTestAliasAgain2.db", 0);
+    testReadDatabase("dbStaticTestAliasAgain3.db", 0);
+    testReadDatabase("dbStaticTestAliasAgain3.db", 0);
+    testReadDatabase("dbStaticTestAliasAgainError1.db", 1);
+    testReadDatabase("dbStaticTestAliasAgainError2.db", 1);
+    dbRecordsOnceOnly = 1;
+    testReadDatabase("dbStaticTestAliasAgain2.db", 1);
+    testReadDatabase("dbStaticTestAliasAgain3.db", 1);
 
     testEntry("testrec.VAL");
     testEntry("testalias.VAL");

diff --git a/modules/database/test/ioc/db/dbStaticTestAliasAgain1.db b/modules/database/test/ioc/db/dbStaticTestAliasAgain1.db
@@ -0,0 +1,4 @@
+# Test re-load alias in record
+record(x, "testrecAgain") {
+    alias("testaliasAgain1")
+}
diff --git a/modules/database/test/ioc/db/dbStaticTestAliasAgain2.db b/modules/database/test/ioc/db/dbStaticTestAliasAgain2.db
@@ -0,0 +1,2 @@
+# Test re-load alias for record
+alias("testrecAgain", "testaliasAgain2")
diff --git a/modules/database/test/ioc/db/dbStaticTestAliasAgain3.db b/modules/database/test/ioc/db/dbStaticTestAliasAgain3.db
@@ -0,0 +1,2 @@
+# Test re-load alias for alias
+alias("testaliasAgain2", "testaliasAgain3")
diff --git a/modules/database/test/ioc/db/dbStaticTestAliasAgainError1.db b/modules/database/test/ioc/db/dbStaticTestAliasAgainError1.db
@@ -0,0 +1,2 @@
+# ERROR: alias using name of exising alias for different record
+alias("testrec", "testaliasAgain1")
diff --git a/modules/database/test/ioc/db/dbStaticTestAliasAgainError2.db b/modules/database/test/ioc/db/dbStaticTestAliasAgainError2.db
@@ -0,0 +1,2 @@
+# ERROR: alias using name of exising record fails
+alias("testrecAgain", "testrec")