Add lset::loadArray and JSON parsing

Replace lset::loadLink with lset::loadScalar, add lset::loadArray
Add dbLoadLinkArray() routine to dbLink.h API
New dbConvertJSON.h API for use by dbConstLoadArray()

src/ioc/db/Makefile

@@ -21,6 +21,7 @@ INC += dbChannel.h
 INC += dbConstLink.h
 INC += dbConvert.h
 INC += dbConvertFast.h
+INC += dbConvertJSON.h
 INC += dbDbLink.h
 INC += dbExtractArray.h
 INC += dbEvent.h
@@ -68,6 +69,7 @@ dbCore_SRCS += dbBkpt.c
 dbCore_SRCS += dbChannel.c
 dbCore_SRCS += dbConstLink.c
 dbCore_SRCS += dbConvert.c
+dbCore_SRCS += dbConvertJSON.c
 dbCore_SRCS += dbDbLink.c
 dbCore_SRCS += dbFastLinkConv.c
 dbCore_SRCS += dbExtractArray.c

src/ioc/db/dbCa.c

@@ -709,8 +709,8 @@ static void scanLinkOnce(dbCommon *prec, caLink *pca) {
 }
 
 static lset dbCa_lset = {
-    NULL,
     dbCaRemoveLink,
+    NULL, NULL,
     isConnected,
     getDBFtype, getElements,
     dbCaGetLink,

src/ioc/db/dbConstLink.c

@@ -12,24 +12,19 @@
  *      Current Author: Andrew Johnson
  */
 
-#include <stddef.h>
 #include <stdio.h>
 
-#include "cvtFast.h"
 #include "dbDefs.h"
-#include "errlog.h"
 
 #define epicsExportSharedSymbols
 #include "dbAccessDefs.h"
 #include "dbAddr.h"
-#include "dbBase.h"
 #include "dbCommon.h"
 #include "dbConvertFast.h"
-#include "dbConvert.h"
+#include "dbConvertJSON.h"
 #include "dbFldTypes.h"
 #include "dbLink.h"
 #include "link.h"
-#include "recGbl.h"
 
 /***************************** Constant Links *****************************/
 
@@ -46,14 +41,14 @@ void dbConstAddLink(struct link *plink)
     plink->lset = &dbConst_lset;
 }
 
-static long dbConstLoadLink(struct link *plink, short dbrType, void *pbuffer)
+/**************************** Member functions ****************************/
+
+static long dbConstLoadScalar(struct link *plink, short dbrType, void *pbuffer)
 {
     if (!plink->value.constantStr)
         return S_db_badField;
 
-    plink->lset = &dbConst_lset;
-
-    /* Constant strings are always numeric */
+    /* Constant scalars are always numeric */
     if (dbrType == DBF_MENU || dbrType == DBF_ENUM || dbrType == DBF_DEVICE)
         dbrType = DBF_USHORT;
 
@@ -61,6 +56,19 @@ static long dbConstLoadLink(struct link *plink, short dbrType, void *pbuffer)
             (plink->value.constantStr, pbuffer, NULL);
 }
 
+static long dbConstLoadArray(struct link *plink, short dbrType, void *pbuffer,
+        long *pnReq)
+{
+    if (!plink->value.constantStr)
+        return S_db_badField;
+
+    /* No support for arrays of choice types */
+    if (dbrType == DBF_MENU || dbrType == DBF_ENUM || dbrType == DBF_DEVICE)
+        return S_db_badField;
+
+    return dbPutConvertJSON(plink->value.constantStr, dbrType, pbuffer, pnReq);
+}
+
 static long dbConstGetNelements(const struct link *plink, long *nelements)
 {
     *nelements = 0;
@@ -76,8 +84,9 @@ static long dbConstGetValue(struct link *plink, short dbrType, void *pbuffer,
 }
 
 static lset dbConst_lset = {
-    dbConstLoadLink,
     NULL,
+    dbConstLoadScalar,
+    dbConstLoadArray,
     NULL,
     NULL, dbConstGetNelements,
     dbConstGetValue,

src/ioc/db/dbConvertJSON.c

@@ -0,0 +1,164 @@
+/*************************************************************************\
+* Copyright (c) 2016 UChicago Argonne LLC, as Operator of Argonne
+*     National Laboratory.
+* EPICS BASE is distributed subject to a Software License Agreement found
+* in file LICENSE that is included with this distribution. 
+\*************************************************************************/
+/* dbConvertJSON.c */
+
+#include <string.h>
+#include <stdio.h>
+
+#include "dbDefs.h"
+#include "yajl_alloc.h"
+#include "yajl_parse.h"
+
+#define epicsExportSharedSybols
+#include "dbAccessDefs.h"
+#include "dbConvertFast.h"
+
+typedef long (*FASTCONVERT)();
+
+typedef struct parseContext {
+    int depth;
+    short dbrType;
+    short dbrSize;
+    void *pdest;
+    int elems;
+} parseContext;
+
+static int dbcj_null(void *ctx) {
+    return 0;    /* Illegal */
+}
+
+static int dbcj_boolean(void *ctx, int val) {
+    return 0;    /* Illegal */
+}
+
+static int dbcj_integer(void *ctx, long num) {
+    parseContext *parser = (parseContext *) ctx;
+    epicsInt32 val32 = num;
+    FASTCONVERT conv = dbFastPutConvertRoutine[DBF_LONG][parser->dbrType];
+
+    if (parser->elems > 0) {
+        conv(&val32, parser->pdest, NULL);
+	parser->pdest += parser->dbrSize;
+	parser->elems--;
+    }
+    return 1;
+}
+
+static int dbcj_double(void *ctx, double num) {
+    parseContext *parser = (parseContext *) ctx;
+    FASTCONVERT conv = dbFastPutConvertRoutine[DBF_DOUBLE][parser->dbrType];
+
+    if (parser->elems > 0) {
+        conv(&num, parser->pdest, NULL);
+	parser->pdest += parser->dbrSize;
+	parser->elems--;
+    }
+    return 1;
+}
+
+static int dbcj_string(void *ctx, const unsigned char *val, unsigned int len) {
+    parseContext *parser = (parseContext *) ctx;
+    char *pdest = parser->pdest;
+
+    /* Not attempting to handle char-array fields here, they need more
+     * metadata about the field than we have available at the moment.
+     */
+    if (parser->dbrType != DBF_STRING)
+        return 0; /* Illegal */
+
+    if (parser->elems > 0) {
+        if (len > MAX_STRING_SIZE - 1)
+            len = MAX_STRING_SIZE - 1;
+        strncpy(pdest, (const char *) val, len);
+	pdest[len] = 0;
+    }
+    return 1;
+}
+
+static int dbcj_start_map(void *ctx) {
+    return 0;    /* Illegal */
+}
+
+static int dbcj_map_key(void *ctx, const unsigned char *key, unsigned int len) {
+    return 0;    /* Illegal */
+}
+
+static int dbcj_end_map(void *ctx) {
+    return 0;    /* Illegal */
+}
+
+static int dbcj_start_array(void *ctx) {
+    parseContext *parser = (parseContext *) ctx;
+
+    parser->depth++;
+    return (parser->depth == 1);
+}
+
+static int dbcj_end_array(void *ctx) {
+    parseContext *parser = (parseContext *) ctx;
+
+    parser->depth--;
+    return (parser->depth == 0);
+}
+
+
+static yajl_callbacks dbcj_callbacks = {
+    dbcj_null, dbcj_boolean, dbcj_integer, dbcj_double, NULL, dbcj_string,
+    dbcj_start_map, dbcj_map_key, dbcj_end_map,
+    dbcj_start_array, dbcj_end_array
+};
+
+static const yajl_parser_config dbcj_config =
+    { 0, 0 }; /* allowComments = NO, checkUTF8 = NO */
+
+long dbPutConvertJSON(const char *json, short dbrType,
+    void *pdest, long *pnRequest)
+{
+    parseContext context, *parser = &context;
+    yajl_alloc_funcs dbcj_alloc;
+    yajl_handle yh;
+    yajl_status ys;
+    size_t jlen = strlen(json);
+    long status;
+
+    parser->depth = 0;
+    parser->dbrType = dbrType;
+    parser->dbrSize = dbValueSize(dbrType);
+    parser->pdest = pdest;
+    parser->elems = *pnRequest;
+
+    yajl_set_default_alloc_funcs(&dbcj_alloc);
+    yh = yajl_alloc(&dbcj_callbacks, &dbcj_config, &dbcj_alloc, parser);
+    if (!yh)
+        return S_db_noMemory;
+
+    ys = yajl_parse(yh, (const unsigned char *) json, (unsigned int) jlen);
+    if (ys == yajl_status_insufficient_data)
+        ys = yajl_parse_complete(yh);
+
+    switch (ys) {
+    case yajl_status_ok:
+        *pnRequest -= parser->elems;
+        status = 0;
+        break;
+
+    case yajl_status_error: {
+	unsigned char *err = yajl_get_error(yh, 1,
+            (const unsigned char *) json, (unsigned int) jlen);
+        fprintf(stderr, "dbPutConvertJSON: %s\n", err);
+        yajl_free_error(yh, err);
+        }
+        /* fall through */
+    default:
+        status = S_db_badField;
+    }
+
+    yajl_free(yh);
+    return status;
+}
+
+

src/ioc/db/dbConvertJSON.h

@@ -0,0 +1,27 @@
+/*************************************************************************\
+* Copyright (c) 2016 UChicago Argonne LLC, as Operator of Argonne
+*     National Laboratory.
+* EPICS BASE is distributed subject to a Software License Agreement found
+* in file LICENSE that is included with this distribution. 
+\*************************************************************************/
+/* dbConvertJSON.h */
+
+#ifndef INC_dbConvertJSON_H
+#define INC_dbConvertJSON_H
+
+#include <shareLib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* This name should probably be changed to inclue "array" */
+epicsShareFunc long dbPutConvertJSON(const char *json, short dbrType,
+    void *pdest, long *psize);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* INC_dbConvertJSON_H */
+

src/ioc/db/dbDbLink.c

@@ -98,7 +98,6 @@ static void dbDbRemoveLink(struct dbLocker *locker, struct link *plink)
     plink->value.pv_link.pvlMask = 0;
     plink->value.pv_link.lastGetdbrType = 0;
     plink->type = PV_LINK;
-    plink->lset = NULL;
     ellDelete(&pdbAddr->precord->bklnk, &plink->value.pv_link.backlinknode);
     dbLockSetSplit(locker, plink->precord, pdbAddr->precord);
     free(pdbAddr);
@@ -332,8 +331,8 @@ static void dbDbScanFwdLink(struct link *plink)
 }
 
 static lset dbDb_lset = {
-    NULL,
     dbDbRemoveLink,
+    NULL, NULL,
     dbDbIsConnected,
     dbDbGetDBFtype, dbDbGetElements,
     dbDbGetValue,

src/ioc/db/dbLink.c

@@ -145,8 +145,20 @@ long dbLoadLink(struct link *plink, short dbrType, void *pbuffer)
 {
     lset *plset = plink->lset;
 
-    if (plset->loadLink)
-        return plset->loadLink(plink, dbrType, pbuffer);
+
+    if (plset->loadScalar)
+        return plset->loadScalar(plink, dbrType, pbuffer);
+
+    return S_db_notFound;
+}
+
+long dbLoadLinkArray(struct link *plink, short dbrType, void *pbuffer,
+    long *pnRequest)
+{
+    lset *plset = plink->lset;
+
+    if (plset->loadArray)
+        return plset->loadArray(plink, dbrType, pbuffer, pnRequest);
 
     return S_db_notFound;
 }

src/ioc/db/dbLink.h

@@ -28,8 +28,10 @@ extern "C" {
 struct dbLocker;
 
 typedef struct lset {
-    long (*loadLink)(struct link *plink, short dbrType, void *pbuffer);
     void (*removeLink)(struct dbLocker *locker, struct link *plink);
+    long (*loadScalar)(struct link *plink, short dbrType, void *pbuffer);
+    long (*loadArray)(struct link *plink, short dbrType, void *pbuffer,
+            long *pnRequest);
     int (*isConnected)(const struct link *plink);
     int (*getDBFtype)(const struct link *plink);
     long (*getElements)(const struct link *plink, long *nelements);
@@ -53,11 +55,13 @@ typedef struct lset {
     dbGetAlarm(link, NULL, sevr)
 
 epicsShareFunc void dbInitLink(struct link *plink, short dbfType);
-epicsShareFunc void dbAddLink(struct dbLocker *locker, struct link *plink, short dbfType,
-        DBADDR *ptarget);
+epicsShareFunc void dbAddLink(struct dbLocker *locker, struct link *plink,
+        short dbfType, DBADDR *ptarget);
+epicsShareFunc void dbRemoveLink(struct dbLocker *locker, struct link *plink);
 epicsShareFunc long dbLoadLink(struct link *plink, short dbrType,
         void *pbuffer);
-epicsShareFunc void dbRemoveLink(struct dbLocker *locker, struct link *plink);
+epicsShareFunc long dbLoadLinkArray(struct link *, short dbrType, void *pbuffer,
+        long *pnRequest);
 
 epicsShareFunc long dbGetNelements(const struct link *plink, long *nelements);
 epicsShareFunc int dbIsLinkConnected(const struct link *plink);