Various improvements

* Added new lset::openLink() method, called on JSON_LINKs only
* Cleanup in dbJLink.c to prevent memory leaks.
* Removed jlif::start_parse() method.
* Renamed jlif::end_parse() to end_child, which will be called on
the parent link when a child link has succesfully finished parsing.

src/ioc/db/dbCa.c

@@ -714,7 +714,7 @@ static void scanLinkOnce(dbCommon *prec, caLink *pca) {
 
 static lset dbCa_lset = {
     0, 1, /* not Constant, Volatile */
-    dbCaRemoveLink,
+    NULL, dbCaRemoveLink,
     NULL, NULL, NULL,
     isConnected,
     getDBFtype, getElements,

src/ioc/db/dbConstLink.c

@@ -124,7 +124,7 @@ static long dbConstGetValue(struct link *plink, short dbrType, void *pbuffer,
 
 static lset dbConst_lset = {
     1, 0, /* Constant, not Volatile */
-    NULL,
+    NULL, NULL,
     dbConstLoadScalar,
     dbConstLoadLS,
     dbConstLoadArray,

src/ioc/db/dbDbLink.c

@@ -337,7 +337,7 @@ static void dbDbScanFwdLink(struct link *plink)
 
 static lset dbDb_lset = {
     0, 0, /* not Constant, not Volatile */
-    dbDbRemoveLink,
+    NULL, dbDbRemoveLink,
     NULL, NULL, NULL,
     dbDbIsConnected,
     dbDbGetDBFtype, dbDbGetElements,

src/ioc/db/dbJLink.c

@@ -43,17 +43,13 @@ typedef struct parseContext {
     unsigned key_is_link:1;
 } parseContext;
 
-#define CALLIF(routine) !routine ? jlif_stop : routine
+#define CALL_OR_STOP(routine) !(routine) ? jlif_stop : (routine)
 
-
-static int dbjl_value(parseContext *parser, jlif_result result) {
+static int dbjl_return(parseContext *parser, jlif_result result) {
     jlink *pjlink = parser->pjlink;
 
-    IFDEBUG(10) {
-        printf("dbjl_value(%s@%p, %d)\n", pjlink->pif->name, pjlink, result);
-        printf("    jsonDepth=%d, linkDepth=%d, key_is_link=%d\n",
-            parser->jsonDepth, parser->linkDepth, parser->key_is_link);
-    }
+    IFDEBUG(10)
+        printf("dbjl_return(%s@%p, %d)\n", pjlink->pif->name, pjlink, result);
 
     if (result == jlif_stop && pjlink) {
         jlink *parent;
@@ -65,19 +61,35 @@ static int dbjl_value(parseContext *parser, jlif_result result) {
         pjlink->pif->free_jlink(pjlink);
     }
 
-    if (result == jlif_stop || parser->linkDepth > 0)
-        return result;
+    return result;
+}
+
+static int dbjl_value(parseContext *parser, jlif_result result) {
+    jlink *pjlink = parser->pjlink;
+    jlink *parent;
+
+    IFDEBUG(10) {
+        printf("dbjl_value(%s@%p, %d)\n", pjlink->pif->name, pjlink, result);
+        printf("    jsonDepth=%d, linkDepth=%d, key_is_link=%d\n",
+            parser->jsonDepth, parser->linkDepth, parser->key_is_link);
+    }
+
+    if (result == jlif_stop || parser->linkDepth > 0)
+        return dbjl_return(parser, result);
+
+    parent = pjlink->parent;
+    if (!parent)
+        parser->product = pjlink;
+   else if (parent->pif->end_child)
+        parent->pif->end_child(parent, pjlink);
 
-    parser->product = pjlink;
     parser->key_is_link = 0;
-    if (pjlink)
-        parser->pjlink = pjlink->parent;
+    parser->pjlink = parent;
 
     IFDEBUG(8)
         printf("dbjl_value: product = %p\n", pjlink);
 
-    return pjlink->pif->end_parse ? pjlink->pif->end_parse(pjlink)
-        : jlif_continue;
+    return jlif_continue;
 }
 
 static int dbjl_null(void *ctx) {
@@ -88,7 +100,8 @@ static int dbjl_null(void *ctx) {
         printf("dbjl_null(%s@%p)\n", pjlink->pif->name, pjlink);
 
     assert(pjlink);
-    return dbjl_value(parser, CALLIF(pjlink->pif->parse_null)(pjlink));
+    return dbjl_value(parser,
+        CALL_OR_STOP(pjlink->pif->parse_null)(pjlink));
 }
 
 static int dbjl_boolean(void *ctx, int val) {
@@ -96,7 +109,8 @@ static int dbjl_boolean(void *ctx, int val) {
     jlink *pjlink = parser->pjlink;
 
     assert(pjlink);
-    return dbjl_value(parser, CALLIF(pjlink->pif->parse_boolean)(pjlink, val));
+    return dbjl_value(parser,
+        CALL_OR_STOP(pjlink->pif->parse_boolean)(pjlink, val));
 }
 
 static int dbjl_integer(void *ctx, long num) {
@@ -104,10 +118,12 @@ static int dbjl_integer(void *ctx, long num) {
     jlink *pjlink = parser->pjlink;
 
     IFDEBUG(10)
-        printf("dbjl_integer(%s@%p, %ld)\n", pjlink->pif->name, pjlink, num);
+        printf("dbjl_integer(%s@%p, %ld)\n",
+            pjlink->pif->name, pjlink, num);
 
     assert(pjlink);
-    return dbjl_value(parser, CALLIF(pjlink->pif->parse_integer)(pjlink, num));
+    return dbjl_value(parser,
+        CALL_OR_STOP(pjlink->pif->parse_integer)(pjlink, num));
 }
 
 static int dbjl_double(void *ctx, double num) {
@@ -115,10 +131,12 @@ static int dbjl_double(void *ctx, double num) {
     jlink *pjlink = parser->pjlink;
 
     IFDEBUG(10)
-        printf("dbjl_double(%s@%p, %g)\n", pjlink->pif->name, pjlink, num);
+        printf("dbjl_double(%s@%p, %g)\n",
+            pjlink->pif->name, pjlink, num);
 
     assert(pjlink);
-    return dbjl_value(parser, CALLIF(pjlink->pif->parse_double)(pjlink, num));
+    return dbjl_value(parser,
+        CALL_OR_STOP(pjlink->pif->parse_double)(pjlink, num));
 }
 
 static int dbjl_string(void *ctx, const unsigned char *val, unsigned len) {
@@ -126,11 +144,12 @@ static int dbjl_string(void *ctx, const unsigned char *val, unsigned len) {
     jlink *pjlink = parser->pjlink;
 
     IFDEBUG(10)
-        printf("dbjl_string(%s@%p, \"%.*s\")\n", pjlink->pif->name, pjlink, len, val);
+        printf("dbjl_string(%s@%p, \"%.*s\")\n",
+            pjlink->pif->name, pjlink, len, val);
 
     assert(pjlink);
     return dbjl_value(parser,
-        CALLIF(pjlink->pif->parse_string)(pjlink, (const char *) val, len));
+        CALL_OR_STOP(pjlink->pif->parse_string)(pjlink, (const char *) val, len));
 }
 
 static int dbjl_start_map(void *ctx) {
@@ -159,8 +178,9 @@ static int dbjl_start_map(void *ctx) {
 
     parser->linkDepth++;
     parser->jsonDepth++;
-    result = CALLIF(pjlink->pif->parse_start_map)(pjlink);
-    if (result == jlif_key_embed_link) {
+
+    result = CALL_OR_STOP(pjlink->pif->parse_start_map)(pjlink);
+    if (result == jlif_key_child_link) {
         parser->key_is_link = 1;
         result = jlif_continue;
     }
@@ -168,7 +188,7 @@ static int dbjl_start_map(void *ctx) {
     IFDEBUG(10)
         printf("dbjl_start_map -> %d\n", result);
 
-    return result;
+    return dbjl_return(parser, result);
 }
 
 static int dbjl_map_key(void *ctx, const unsigned char *key, unsigned len) {
@@ -178,13 +198,12 @@ static int dbjl_map_key(void *ctx, const unsigned char *key, unsigned len) {
     size_t lnlen = len;
     linkSup *linkSup;
     jlif *pjlif;
-    jlif_result result;
 
     if (!parser->key_is_link) {
         if (!pjlink) {
             errlogPrintf("dbJLinkInit: Illegal second link key '%.*s'\n",
                 len, key);
-            return jlif_stop;
+            return dbjl_return(parser, jlif_stop);
         }
 
         IFDEBUG(10) {
@@ -195,7 +214,9 @@ static int dbjl_map_key(void *ctx, const unsigned char *key, unsigned len) {
         }
 
         assert(parser->linkDepth > 0);
-        return CALLIF(pjlink->pif->parse_map_key)(pjlink, (const char *) key, len);
+        return dbjl_return(parser,
+            CALL_OR_STOP(pjlink->pif->parse_map_key)(pjlink,
+                (const char *) key, len));
     }
 
     IFDEBUG(10) {
@@ -213,44 +234,35 @@ static int dbjl_map_key(void *ctx, const unsigned char *key, unsigned len) {
     if (!linkSup) {
         errlogPrintf("dbJLinkInit: Link type '%s' not found\n",
             link_name);
-        return jlif_stop;
+        return dbjl_return(parser, jlif_stop);
     }
 
     pjlif = linkSup->pjlif;
     if (!pjlif) {
         errlogPrintf("dbJLinkInit: Support for Link type '%s' not loaded\n",
             link_name);
-        return jlif_stop;
+        return dbjl_return(parser, jlif_stop);
     }
 
     pjlink = pjlif->alloc_jlink(parser->dbfType);
     if (!pjlink) {
         errlogPrintf("dbJLinkInit: Out of memory\n");
-        return jlif_stop;
+        return dbjl_return(parser, jlif_stop);
     }
     pjlink->pif = pjlif;
 
     if (parser->pjlink) {
-        /* This is an embedded link */
+        /* We're starting a child link, save its parent */
         pjlink->parent = parser->pjlink;
     }
+    parser->pjlink = pjlink;
 
-    result = pjlif->start_parse ? pjlif->start_parse(pjlink) : jlif_continue;
-    if (result == jlif_continue) {
-        parser->pjlink = pjlink;
+    IFDEBUG(8)
+        printf("dbjl_map_key: New %s@%p\n", pjlink->pif->name, pjlink);
 
-        IFDEBUG(8)
-            printf("dbjl_map_key: New %s@%p\n", pjlink->pif->name, pjlink);
-    }
-    else {
-        pjlif->free_jlink(pjlink);
-    }
-    // FIXME Ensure link map has only one link key...
+    // FIXME How to ensure a link map has only one key/value pair?
 
-    IFDEBUG(10)
-        printf("dbjl_map_key -> %d\n", result);
-
-    return result;
+    return jlif_continue;
 }
 
 static int dbjl_end_map(void *ctx) {
@@ -269,7 +281,8 @@ static int dbjl_end_map(void *ctx) {
     if (parser->linkDepth > 0) {
         parser->linkDepth--;
 
-        result = dbjl_value(parser, CALLIF(pjlink->pif->parse_end_map)(pjlink));
+        result = dbjl_value(parser,
+            CALL_OR_STOP(pjlink->pif->parse_end_map)(pjlink));
     }
     else {
         result = jlif_continue;
@@ -290,7 +303,9 @@ static int dbjl_start_array(void *ctx) {
     assert(pjlink);
     parser->linkDepth++;
     parser->jsonDepth++;
-    return CALLIF(pjlink->pif->parse_start_array)(pjlink);
+
+    return dbjl_return(parser,
+        CALL_OR_STOP(pjlink->pif->parse_start_array)(pjlink));
 }
 
 static int dbjl_end_array(void *ctx) {
@@ -306,9 +321,12 @@ static int dbjl_end_array(void *ctx) {
     assert(pjlink);
     parser->linkDepth--;
     parser->jsonDepth--;
-    return dbjl_value(parser, CALLIF(pjlink->pif->parse_end_array)(pjlink));
+
+    return dbjl_value(parser,
+        CALL_OR_STOP(pjlink->pif->parse_end_array)(pjlink));
 }
 
+
 static yajl_callbacks dbjl_callbacks = {
     dbjl_null, dbjl_boolean, dbjl_integer, dbjl_double, NULL, dbjl_string,
     dbjl_start_map, dbjl_map_key, dbjl_end_map, dbjl_start_array, dbjl_end_array
@@ -380,7 +398,8 @@ long dbJLinkInit(struct link *plink)
     pjlink = plink->value.json.jlink;
 
     if (pjlink)
-        plink->lset = pjlink->pif->get_lset(pjlink, plink);
+        plink->lset = pjlink->pif->get_lset(pjlink);
 
+    dbLinkOpen(plink);
     return 0;
 }

src/ioc/db/dbJLink.h

@@ -27,7 +27,7 @@ typedef enum {
 typedef enum {
     jlif_key_stop = jlif_stop,
     jlif_key_continue = jlif_continue,
-    jlif_key_embed_link
+    jlif_key_child_link
 } jlif_key_result;
 
 struct link;
@@ -44,7 +44,6 @@ typedef struct jlif {
     const char *name;
     jlink* (*alloc_jlink)(short dbfType);
     void (*free_jlink)(jlink *);
-    jlif_result (*start_parse)(jlink *);
     jlif_result (*parse_null)(jlink *);
     jlif_result (*parse_boolean)(jlink *, int val);
     jlif_result (*parse_integer)(jlink *, long num);
@@ -55,8 +54,8 @@ typedef struct jlif {
     jlif_result (*parse_end_map)(jlink *);
     jlif_result (*parse_start_array)(jlink *);
     jlif_result (*parse_end_array)(jlink *);
-    jlif_result (*end_parse)(jlink *);
-    struct lset* (*get_lset)(const jlink *, struct link *);
+    void (*end_child)(jlink *parent, jlink *child);
+    struct lset* (*get_lset)(const jlink *);
     void (*report)(const jlink *);
 } jlif;
 

src/ioc/db/dbLink.c

@@ -160,6 +160,14 @@ void dbAddLink(struct dbLocker *locker, struct link *plink, short dbfType,
     }
 }
 
+void dbLinkOpen(struct link *plink)
+{
+    lset *plset = plink->lset;
+
+    if (plset && plset->openLink)
+        plset->openLink(plink);
+}
+
 void dbRemoveLink(struct dbLocker *locker, struct link *plink)
 {
     lset *plset = plink->lset;

src/ioc/db/dbLink.h

@@ -32,6 +32,9 @@ typedef struct lset {
     const unsigned isConstant:1;
     const unsigned isVolatile:1;
 
+    /* Activation */
+    void (*openLink)(struct link *plink);
+
     /* Destructor */
     void (*removeLink)(struct dbLocker *locker, struct link *plink);
 
@@ -76,6 +79,8 @@ typedef struct lset {
 epicsShareFunc void dbInitLink(struct link *plink, short dbfType);
 epicsShareFunc void dbAddLink(struct dbLocker *locker, struct link *plink,
         short dbfType, DBADDR *ptarget);
+
+epicsShareFunc void dbLinkOpen(struct link *plink);
 epicsShareFunc void dbRemoveLink(struct dbLocker *locker, struct link *plink);
 
 epicsShareFunc int dbLinkIsDefined(const struct link *plink);  /* 0 or 1 */

src/std/link/lnkConst.c

@@ -275,9 +275,9 @@ static jlif_result lnkConst_end_array(jlink *pjlink) {
     return jlif_continue;
 }
 
-static struct lset* lnkConst_get_lset(const jlink *pjlink, struct link *plink) {
+static struct lset* lnkConst_get_lset(const jlink *pjlink) {
     IFDEBUG(10)
-        printf("lnkConst_get_lset(const@%p, %p)\n", pjlink, plink);
+        printf("lnkConst_get_lset(const@%p)\n", pjlink);
 
     return &lnkConst_lset;
 }
@@ -466,7 +466,8 @@ static long lnkConst_getValue(struct link *plink, short dbrType, void *pbuffer,
 
 static lset lnkConst_lset = {
     1, 0, /* Constant, not Volatile */
-    NULL, lnkConst_loadScalar, lnkConst_loadLS, lnkConst_loadArray, NULL,
+    NULL, NULL,
+    lnkConst_loadScalar, lnkConst_loadLS, lnkConst_loadArray, NULL,
     NULL, lnkConst_getNelements, lnkConst_getValue,
     NULL, NULL, NULL,
     NULL, NULL,
@@ -476,7 +477,7 @@ static lset lnkConst_lset = {
 };
 
 static jlif lnkConstIf = {
-    "const", lnkConst_alloc, lnkConst_free, NULL,
+    "const", lnkConst_alloc, lnkConst_free,
     NULL, lnkConst_boolean, lnkConst_integer, lnkConst_double, lnkConst_string,
     NULL, NULL, NULL, lnkConst_start_array, lnkConst_end_array,
     NULL, lnkConst_get_lset, lnkConst_report