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/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;
+}
+
+