Hi Tom,

On 1/14/20 9:47 PM, Tom Lane wrote:
David Steele <da...@pgmasters.net> writes:
I'm happy to work up a prototype unless the consensus is that we
absolutely don't want a second JSON parser in core.

How much code are we talking about?  If the answer is "a few hundred
lines", it's a lot easier to swallow than if it's "a few thousand".

It's currently about a thousand lines but we have a lot of functions to convert to/from specific types. I imagine the line count would be similar using one of the approaches I discussed above.

Current source attached for reference.

Regards,
--
-David
da...@pgmasters.net
/***********************************************************************************************************************************
Convert JSON to/from KeyValue
***********************************************************************************************************************************/
#include "build.auto.h"

#include <ctype.h>
#include <string.h>

#include "common/debug.h"
#include "common/log.h"
#include "common/type/json.h"

/***********************************************************************************************************************************
Prototypes
***********************************************************************************************************************************/
static Variant *jsonToVarInternal(const char *json, unsigned int *jsonPos);

/***********************************************************************************************************************************
Consume whitespace
***********************************************************************************************************************************/
static void
jsonConsumeWhiteSpace(const char *json, unsigned int *jsonPos)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRINGZ, json);
        FUNCTION_TEST_PARAM_P(UINT, jsonPos);
    FUNCTION_TEST_END();

    // Consume whitespace
    while (json[*jsonPos] == ' ' || json[*jsonPos] == '\t' || json[*jsonPos] == 
'\n'  || json[*jsonPos] == '\r')
        (*jsonPos)++;

    FUNCTION_TEST_RETURN_VOID();
}

/***********************************************************************************************************************************
Convert a json string to a bool
***********************************************************************************************************************************/
static bool
jsonToBoolInternal(const char *json, unsigned int *jsonPos)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRINGZ, json);
        FUNCTION_TEST_PARAM_P(UINT, jsonPos);
    FUNCTION_TEST_END();

    bool result;

    if (strncmp(json + *jsonPos, TRUE_Z, 4) == 0)
    {
        result = true;
        *jsonPos += 4;
    }
    else if (strncmp(json + *jsonPos, FALSE_Z, 5) == 0)
    {
        result = false;
        *jsonPos += 5;
    }
    else
        THROW_FMT(JsonFormatError, "expected boolean at '%s'", json + *jsonPos);

    FUNCTION_TEST_RETURN(result);
}

bool
jsonToBool(const String *json)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRING, json);
    FUNCTION_TEST_END();

    unsigned int jsonPos = 0;
    jsonConsumeWhiteSpace(strPtr(json), &jsonPos);

    bool result = jsonToBoolInternal(strPtr(json), &jsonPos);

    jsonConsumeWhiteSpace(strPtr(json), &jsonPos);

    if (jsonPos != strSize(json))
        THROW_FMT(JsonFormatError, "unexpected characters after boolean at 
'%s'", strPtr(json) + jsonPos);

    FUNCTION_TEST_RETURN(result);
}

/***********************************************************************************************************************************
Convert a json number to various integer types
***********************************************************************************************************************************/
static Variant *
jsonToNumberInternal(const char *json, unsigned int *jsonPos)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRINGZ, json);
        FUNCTION_TEST_PARAM_P(UINT, jsonPos);
    FUNCTION_TEST_END();

    Variant *result = NULL;
    unsigned int beginPos = *jsonPos;
    bool intSigned = false;

    // Consume the -
    if (json[*jsonPos] == '-')
    {
        (*jsonPos)++;
        intSigned = true;
    }

    // Consume all digits
    while (isdigit(json[*jsonPos]))
        (*jsonPos)++;

    // Invalid if only a - was found
    if (json[*jsonPos - 1] == '-')
        THROW_FMT(JsonFormatError, "found '-' with no integer at '%s'", json + 
beginPos);

    MEM_CONTEXT_TEMP_BEGIN()
    {
        // Extract the numeric as a string
        String *resultStr = strNewN(json + beginPos, *jsonPos - beginPos);

        // Convert the string to a integer variant
        memContextSwitch(MEM_CONTEXT_OLD());

        if (intSigned)
            result = varNewInt64(cvtZToInt64(strPtr(resultStr)));
        else
            result = varNewUInt64(cvtZToUInt64(strPtr(resultStr)));

        memContextSwitch(MEM_CONTEXT_TEMP());
    }
    MEM_CONTEXT_TEMP_END();

    FUNCTION_TEST_RETURN(result);
}

static Variant *
jsonToNumber(const String *json)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRING, json);
    FUNCTION_TEST_END();

    unsigned int jsonPos = 0;
    jsonConsumeWhiteSpace(strPtr(json), &jsonPos);

    Variant *result = jsonToNumberInternal(strPtr(json), &jsonPos);

    jsonConsumeWhiteSpace(strPtr(json), &jsonPos);

    if (jsonPos != strSize(json))
        THROW_FMT(JsonFormatError, "unexpected characters after number at 
'%s'", strPtr(json) + jsonPos);

    FUNCTION_TEST_RETURN(result);
}

int
jsonToInt(const String *json)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRING, json);
    FUNCTION_TEST_END();

    int result = 0;

    MEM_CONTEXT_TEMP_BEGIN()
    {
        result = varIntForce(jsonToNumber(json));
    }
    MEM_CONTEXT_TEMP_END();

    FUNCTION_TEST_RETURN(result);
}

int64_t
jsonToInt64(const String *json)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRING, json);
    FUNCTION_TEST_END();

    int64_t result = 0;

    MEM_CONTEXT_TEMP_BEGIN()
    {
        result = varInt64Force(jsonToNumber(json));
    }
    MEM_CONTEXT_TEMP_END();

    FUNCTION_TEST_RETURN(result);
}

unsigned int
jsonToUInt(const String *json)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRING, json);
    FUNCTION_TEST_END();

    unsigned int result = 0;

    MEM_CONTEXT_TEMP_BEGIN()
    {
        result = varUIntForce(jsonToNumber(json));
    }
    MEM_CONTEXT_TEMP_END();

    FUNCTION_TEST_RETURN(result);
}

uint64_t
jsonToUInt64(const String *json)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRING, json);
    FUNCTION_TEST_END();

    uint64_t result = 0;

    MEM_CONTEXT_TEMP_BEGIN()
    {
        result = varUInt64Force(jsonToNumber(json));
    }
    MEM_CONTEXT_TEMP_END();

    FUNCTION_TEST_RETURN(result);
}

/***********************************************************************************************************************************
Convert a json string to a String
***********************************************************************************************************************************/
static String *
jsonToStrInternal(const char *json, unsigned int *jsonPos)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRINGZ, json);
        FUNCTION_TEST_PARAM_P(UINT, jsonPos);
    FUNCTION_TEST_END();

    String *result = strNew("");

    if (json[*jsonPos] != '"')
        THROW_FMT(JsonFormatError, "expected '\"' at '%s'", json + *jsonPos);

    MEM_CONTEXT_TEMP_BEGIN()
    {
        (*jsonPos)++;

        while (json[*jsonPos] != '"')
        {
            if (json[*jsonPos] == '\\')
            {
                (*jsonPos)++;;

                switch (json[*jsonPos])
                {
                    case '"':
                            strCatChr(result, '"');
                        break;

                    case '\\':
                            strCatChr(result, '\\');
                        break;

                    case '/':
                            strCatChr(result, '/');
                        break;

                    case 'n':
                            strCatChr(result, '\n');
                        break;

                    case 'r':
                            strCatChr(result, '\r');
                        break;

                    case 't':
                            strCatChr(result, '\t');
                        break;

                    case 'b':
                            strCatChr(result, '\b');
                        break;

                    case 'f':
                            strCatChr(result, '\f');
                        break;

                    default:
                        THROW_FMT(JsonFormatError, "invalid escape character 
'%c'", json[*jsonPos]);
                }
            }
            else
            {
                if (json[*jsonPos] == '\0')
                    THROW(JsonFormatError, "expected '\"' but found null 
delimiter");

                    strCatChr(result, json[*jsonPos]);
            }

            (*jsonPos)++;;
        };

        // Advance the character array pointer to the next element after the 
string
        (*jsonPos)++;;
    }
    MEM_CONTEXT_TEMP_END();

    FUNCTION_TEST_RETURN(result);
}

String *
jsonToStr(const String *json)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRING, json);
    FUNCTION_TEST_END();

    unsigned int jsonPos = 0;
    jsonConsumeWhiteSpace(strPtr(json), &jsonPos);

    String *result = NULL;

    if (strncmp(strPtr(json), NULL_Z, 4) == 0)
        jsonPos += 4;
    else
        result = jsonToStrInternal(strPtr(json), &jsonPos);

    jsonConsumeWhiteSpace(strPtr(json), &jsonPos);

    if (jsonPos != strSize(json))
        THROW_FMT(JsonFormatError, "unexpected characters after string at 
'%s'", strPtr(json) + jsonPos);

    FUNCTION_TEST_RETURN(result);
}

/***********************************************************************************************************************************
Convert a json object to a KeyValue
***********************************************************************************************************************************/
static KeyValue *
jsonToKvInternal(const char *json, unsigned int *jsonPos)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRINGZ, json);
        FUNCTION_TEST_PARAM_P(UINT, jsonPos);
    FUNCTION_TEST_END();

    KeyValue *result = kvNew();

    MEM_CONTEXT_TEMP_BEGIN()
    {
        // Move position to the first key/value in the object
        (*jsonPos)++;
        jsonConsumeWhiteSpace(json, jsonPos);

        // Only proceed if the array is not empty
        if (json[*jsonPos] != '}')
        {
            do
            {
                if (json[*jsonPos] == ',')
                {
                    (*jsonPos)++;
                    jsonConsumeWhiteSpace(json, jsonPos);
                }

                Variant *key = varNewStr(jsonToStrInternal(json, jsonPos));

                jsonConsumeWhiteSpace(json, jsonPos);

                if (json[*jsonPos] != ':')
                    THROW_FMT(JsonFormatError, "expected ':' at '%s'", json + 
*jsonPos);
                (*jsonPos)++;

                jsonConsumeWhiteSpace(json, jsonPos);

                kvPut(result, key, jsonToVarInternal(json, jsonPos));
            }
            while (json[*jsonPos] == ',');
        }

        if (json[*jsonPos] != '}')
            THROW_FMT(JsonFormatError, "expected '}' at '%s'", json + *jsonPos);
        (*jsonPos)++;
    }
    MEM_CONTEXT_TEMP_END();

    FUNCTION_TEST_RETURN(result);
}

KeyValue *
jsonToKv(const String *json)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRING, json);
    FUNCTION_TEST_END();

    unsigned int jsonPos = 0;
    jsonConsumeWhiteSpace(strPtr(json), &jsonPos);

    if (strPtr(json)[jsonPos] != '{')
        THROW_FMT(JsonFormatError, "expected '{' at '%s'", strPtr(json) + 
jsonPos);

    KeyValue *result = jsonToKvInternal(strPtr(json), &jsonPos);

    jsonConsumeWhiteSpace(strPtr(json), &jsonPos);

    if (jsonPos != strSize(json))
        THROW_FMT(JsonFormatError, "unexpected characters after object at 
'%s'", strPtr(json) + jsonPos);

    FUNCTION_TEST_RETURN(result);
}

/***********************************************************************************************************************************
Convert a json string to an array
***********************************************************************************************************************************/
static VariantList *
jsonToVarLstInternal(const char *json, unsigned int *jsonPos)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRINGZ, json);
        FUNCTION_TEST_PARAM_P(UINT, jsonPos);
    FUNCTION_TEST_END();

    VariantList *result = varLstNew();

    if (json[*jsonPos] != '[')
        THROW_FMT(JsonFormatError, "expected '[' at '%s'", json + *jsonPos);

    MEM_CONTEXT_TEMP_BEGIN()
    {
        // Move position to the first element in the array
        (*jsonPos)++;
        jsonConsumeWhiteSpace(json, jsonPos);

        // Only proceed if the array is not empty
        if (json[*jsonPos] != ']')
        {
            do
            {
                if (json[*jsonPos] == ',')
                {
                    (*jsonPos)++;
                    jsonConsumeWhiteSpace(json, jsonPos);
                }

                memContextSwitch(MEM_CONTEXT_OLD());
                varLstAdd(result, jsonToVarInternal(json, jsonPos));
                memContextSwitch(MEM_CONTEXT_TEMP());

                jsonConsumeWhiteSpace(json, jsonPos);
            }
            while (json[*jsonPos] == ',');
        }

        if (json[*jsonPos] != ']')
            THROW_FMT(JsonFormatError, "expected ']' at '%s'", json + *jsonPos);

        (*jsonPos)++;
    }
    MEM_CONTEXT_TEMP_END();

    FUNCTION_TEST_RETURN(result);
}

VariantList *
jsonToVarLst(const String *json)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRING, json);
    FUNCTION_TEST_END();

    unsigned int jsonPos = 0;
    jsonConsumeWhiteSpace(strPtr(json), &jsonPos);

    VariantList *result = jsonToVarLstInternal(strPtr(json), &jsonPos);

    jsonConsumeWhiteSpace(strPtr(json), &jsonPos);

    if (jsonPos != strSize(json))
        THROW_FMT(JsonFormatError, "unexpected characters after array at '%s'", 
strPtr(json) + jsonPos);

    FUNCTION_TEST_RETURN(result);
}

/***********************************************************************************************************************************
Convert JSON to a variant
***********************************************************************************************************************************/
static Variant *
jsonToVarInternal(const char *json, unsigned int *jsonPos)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRINGZ, json);
        FUNCTION_TEST_PARAM_P(UINT, jsonPos);
    FUNCTION_TEST_END();

    Variant *result = NULL;

    jsonConsumeWhiteSpace(json, jsonPos);

    // There should be some data
    if (json[*jsonPos] == '\0')
        THROW(JsonFormatError, "expected data");

    // Determine data type
    switch (json[*jsonPos])
    {
        // String
        case '"':
        {
            result = varNewStr(jsonToStrInternal(json, jsonPos));
            break;
        }

        // Integer
        case '-':
        case '0' ... '9':
        {
            result = jsonToNumberInternal(json, jsonPos);
            break;
        }

        // Boolean
        case 't':
        case 'f':
        {
            result = varNewBool(jsonToBoolInternal(json, jsonPos));
            break;
        }

        // Null
        case 'n':
        {
            if (strncmp(json + *jsonPos, NULL_Z, 4) == 0)
                *jsonPos += 4;
            else
                THROW_FMT(JsonFormatError, "expected null at '%s'", json + 
*jsonPos);

            break;
        }

        // Array
        case '[':
        {
            result = varNewVarLst(jsonToVarLstInternal(json, jsonPos));
            break;
        }

        // Object
        case '{':
        {
            result = varNewKv(jsonToKvInternal(json, jsonPos));
            break;
        }

        // Object
        default:
        {
            THROW_FMT(JsonFormatError, "invalid type at '%s'", json + *jsonPos);
            break;
        }
    }

    jsonConsumeWhiteSpace(json, jsonPos);

    FUNCTION_TEST_RETURN(result);
}

Variant *
jsonToVar(const String *json)
{
    FUNCTION_LOG_BEGIN(logLevelTrace);
        FUNCTION_LOG_PARAM(STRING, json);
    FUNCTION_LOG_END();

    const char *jsonPtr = strPtr(json);
    unsigned int jsonPos = 0;

    FUNCTION_LOG_RETURN(VARIANT, jsonToVarInternal(jsonPtr, &jsonPos));
}

/***********************************************************************************************************************************
Convert a boolean to JSON
***********************************************************************************************************************************/
const String *
jsonFromBool(bool value)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(BOOL, value);
    FUNCTION_TEST_END();

    FUNCTION_TEST_RETURN(value ? TRUE_STR : FALSE_STR);
}

/***********************************************************************************************************************************
Convert a number to JSON
***********************************************************************************************************************************/
String *
jsonFromInt(int number)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(INT, number);
    FUNCTION_TEST_END();

    char working[CVT_BASE10_BUFFER_SIZE];
    cvtIntToZ(number, working, sizeof(working));

    FUNCTION_TEST_RETURN(strNew(working));
}

String *
jsonFromInt64(int64_t number)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(INT64, number);
    FUNCTION_TEST_END();

    char working[CVT_BASE10_BUFFER_SIZE];
    cvtInt64ToZ(number, working, sizeof(working));

    FUNCTION_TEST_RETURN(strNew(working));
}

String *
jsonFromUInt(unsigned int number)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(UINT, number);
    FUNCTION_TEST_END();

    char working[CVT_BASE10_BUFFER_SIZE];
    cvtUIntToZ(number, working, sizeof(working));

    FUNCTION_TEST_RETURN(strNew(working));
}

String *
jsonFromUInt64(uint64_t number)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(UINT64, number);
    FUNCTION_TEST_END();

    char working[CVT_BASE10_BUFFER_SIZE];
    cvtUInt64ToZ(number, working, sizeof(working));

    FUNCTION_TEST_RETURN(strNew(working));
}

/***********************************************************************************************************************************
Output and escape a string
***********************************************************************************************************************************/
static void
jsonFromStrInternal(String *json, const String *string)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRING, json);
        FUNCTION_TEST_PARAM(STRING, string);
    FUNCTION_TEST_END();

    ASSERT(json != NULL);

    // If string is null
    if (string == NULL)
    {
        strCat(json, NULL_Z);
    }
    // Else escape and output string
    else
    {
        strCatChr(json, '"');

        for (unsigned int stringIdx = 0; stringIdx < strSize(string); 
stringIdx++)
        {
            char stringChr = strPtr(string)[stringIdx];

            switch (stringChr)
            {
                case '"':
                    strCat(json, "\\\"");
                    break;

                case '\\':
                    strCat(json, "\\\\");
                    break;

                case '\n':
                    strCat(json, "\\n");
                    break;

                case '\r':
                    strCat(json, "\\r");
                    break;

                case '\t':
                    strCat(json, "\\t");
                    break;

                case '\b':
                    strCat(json, "\\b");
                    break;

                case '\f':
                    strCat(json, "\\f");
                    break;

                default:
                    strCatChr(json, stringChr);
                    break;
            }
        }

        strCatChr(json, '"');
    }

    FUNCTION_TEST_RETURN_VOID();
}

String *
jsonFromStr(const String *string)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(STRING, string);
    FUNCTION_TEST_END();

    String *json = strNew("");
    jsonFromStrInternal(json, string);

    FUNCTION_TEST_RETURN(json);
}

/***********************************************************************************************************************************
Internal recursive function to walk a KeyValue and return a json string
***********************************************************************************************************************************/
static String *
jsonFromKvInternal(const KeyValue *kv)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(KEY_VALUE, kv);
    FUNCTION_TEST_END();

    ASSERT(kv != NULL);

    String *result = strNew("{");

    MEM_CONTEXT_TEMP_BEGIN()
    {
        const StringList *keyList = strLstSort(strLstNewVarLst(kvKeyList(kv)), 
sortOrderAsc);

        for (unsigned int keyIdx = 0; keyIdx < strLstSize(keyList); keyIdx++)
        {
            String *key = strLstGet(keyList, keyIdx);
            const Variant *value = kvGet(kv, VARSTR(key));

            // If going to add another key, prepend a comma
            if (keyIdx > 0)
                strCat(result, ",");

            // Keys are always strings in the output, so add starting quote and 
colon.
            strCatFmt(result, "\"%s\":", strPtr(key));

            // NULL value
            if (value == NULL)
                strCat(result, NULL_Z);
            else
            {
                switch (varType(value))
                {
                    case varTypeKeyValue:
                    {
                        strCat(result, 
strPtr(jsonFromKvInternal(kvDup(varKv(value)))));
                        break;
                    }

                    case varTypeVariantList:
                    {
                        // If the array is empty, then do not add formatting, 
else process the array.
                        if (varVarLst(value) == NULL)
                            strCat(result, NULL_Z);
                        else if (varLstSize(varVarLst(value)) == 0)
                            strCat(result, "[]");
                        else
                        {
                            strCat(result, "[");

                            for (unsigned int arrayIdx = 0; arrayIdx < 
varLstSize(varVarLst(value)); arrayIdx++)
                            {
                                Variant *arrayValue = 
varLstGet(varVarLst(value), arrayIdx);

                                // If going to add another element, add a comma
                                if (arrayIdx > 0)
                                    strCat(result, ",");

                                // If array value is null
                                if (arrayValue == NULL)
                                {
                                    strCat(result, NULL_Z);
                                }
                                // If the type is a string, add leading and 
trailing double quotes
                                else if (varType(arrayValue) == varTypeString)
                                {
                                    jsonFromStrInternal(result, 
varStr(arrayValue));
                                }
                                else if (varType(arrayValue) == varTypeKeyValue)
                                {
                                    strCat(result, 
strPtr(jsonFromKvInternal(kvDup(varKv(arrayValue)))));
                                }
                                else if (varType(arrayValue) == 
varTypeVariantList)
                                {
                                    strCat(result, 
strPtr(jsonFromVar(arrayValue)));
                                }
                                // Numeric, Boolean or other type
                                else
                                    strCat(result, 
strPtr(varStrForce(arrayValue)));
                            }

                            strCat(result, "]");
                        }

                        break;
                    }

                    // String
                    case varTypeString:
                    {
                        jsonFromStrInternal(result, varStr(value));
                        break;
                    }

                    default:
                    {
                        strCat(result, strPtr(varStrForce(value)));
                        break;
                    }
                }
            }
        }

        result = strCat(result, "}");
    }
    MEM_CONTEXT_TEMP_END();

    FUNCTION_TEST_RETURN(result);
}

/***********************************************************************************************************************************
Convert KeyValue object to JSON string.

Currently this function is only intended to convert the limited types that are 
included in info files.  More types will be added as
needed.  Since this function is only intended to read internally-generated JSON 
it is assumed to be well-formed with no extraneous
whitespace.
***********************************************************************************************************************************/
String *
jsonFromKv(const KeyValue *kv)
{
    FUNCTION_LOG_BEGIN(logLevelTrace);
        FUNCTION_LOG_PARAM(KEY_VALUE, kv);
    FUNCTION_LOG_END();

    ASSERT(kv != NULL);

    String *result = NULL;

    MEM_CONTEXT_TEMP_BEGIN()
    {
        String *jsonStr = jsonFromKvInternal(kv);

        // Duplicate the string into the calling context
        memContextSwitch(MEM_CONTEXT_OLD());
        result = strDup(jsonStr);
        memContextSwitch(MEM_CONTEXT_TEMP());
    }
    MEM_CONTEXT_TEMP_END();

    FUNCTION_LOG_RETURN(STRING, result);
}

/***********************************************************************************************************************************
Convert Variant object to JSON string.

Currently this function is only intended to convert the limited types that are 
included in info files.  More types will be added as
needed.
***********************************************************************************************************************************/
String *
jsonFromVar(const Variant *var)
{
    FUNCTION_LOG_BEGIN(logLevelTrace);
        FUNCTION_LOG_PARAM(VARIANT, var);
    FUNCTION_LOG_END();

    String *result = NULL;

    MEM_CONTEXT_TEMP_BEGIN()
    {
        String *jsonStr = strNew("");

        // If VariantList then process each item in the array. Currently the 
list must be KeyValue types.
        if (var == NULL)
        {
            strCat(jsonStr, strPtr(NULL_STR));
        }
        else if (varType(var) == varTypeBool)
        {
            strCat(jsonStr, strPtr(jsonFromBool(varBool(var))));
        }
        else if (varType(var) == varTypeUInt)
        {
            strCat(jsonStr, strPtr(jsonFromUInt(varUInt(var))));
        }
        else if (varType(var) == varTypeUInt64)
        {
            strCat(jsonStr, strPtr(jsonFromUInt64(varUInt64(var))));
        }
        else if (varType(var) == varTypeString)
        {
            jsonFromStrInternal(jsonStr, varStr(var));
        }
        else if (varType(var) == varTypeVariantList)
        {
            const VariantList *vl = varVarLst(var);

            // If not an empty array
            if (varLstSize(vl) > 0)
            {
                strCat(jsonStr, "[");

                // Currently only KeyValue and String lists are supported
                for (unsigned int vlIdx = 0; vlIdx < varLstSize(vl); vlIdx++)
                {
                    // If going to add another key, append a comma
                    if (vlIdx > 0)
                        strCat(jsonStr, ",");

                    Variant *varSub = varLstGet(vl, vlIdx);

                    if (varSub == NULL)
                    {
                        strCat(jsonStr, NULL_Z);
                    }
                    else if (varType(varSub) == varTypeBool)
                    {
                        strCat(jsonStr, strPtr(jsonFromBool(varBool(varSub))));
                    }
                    else if (varType(varSub) == varTypeKeyValue)
                    {
                        strCat(jsonStr, 
strPtr(jsonFromKvInternal(varKv(varSub))));
                    }
                    else if (varType(varSub) == varTypeVariantList)
                    {
                        strCat(jsonStr, strPtr(jsonFromVar(varSub)));
                    }
                    else if (varType(varSub) == varTypeInt)
                    {
                        strCat(jsonStr, strPtr(jsonFromInt(varInt(varSub))));
                    }
                    else if (varType(varSub) == varTypeInt64)
                    {
                        strCat(jsonStr, 
strPtr(jsonFromInt64(varInt64(varSub))));
                    }
                    else if (varType(varSub) == varTypeUInt)
                    {
                        strCat(jsonStr, strPtr(jsonFromUInt(varUInt(varSub))));
                    }
                    else if (varType(varSub) == varTypeUInt64)
                    {
                        strCat(jsonStr, 
strPtr(jsonFromUInt64(varUInt64(varSub))));
                    }
                    else
                        jsonFromStrInternal(jsonStr, varStr(varSub));
                }

                // Close the array
                strCat(jsonStr, "]");
            }
            // Else empty array
            else
                strCat(jsonStr, "[]");
        }
        else if (varType(var) == varTypeKeyValue)
        {
            strCat(jsonStr, strPtr(jsonFromKvInternal(varKv(var))));
        }
        else
            THROW(JsonFormatError, "variant type is invalid");

        // Duplicate the string into the calling context
        memContextSwitch(MEM_CONTEXT_OLD());
        result = strDup(jsonStr);
        memContextSwitch(MEM_CONTEXT_TEMP());
    }
    MEM_CONTEXT_TEMP_END();

    FUNCTION_LOG_RETURN(STRING, result);
}
/***********************************************************************************************************************************
Convert JSON to/from KeyValue
***********************************************************************************************************************************/
#ifndef COMMON_TYPE_JSON_H
#define COMMON_TYPE_JSON_H

#include "common/type/keyValue.h"

/***********************************************************************************************************************************
Functions
***********************************************************************************************************************************/
bool jsonToBool(const String *json);
int jsonToInt(const String *json);
int64_t jsonToInt64(const String *json);
KeyValue *jsonToKv(const String *json);
String *jsonToStr(const String *json);
unsigned int jsonToUInt(const String *json);
uint64_t jsonToUInt64(const String *json);
Variant *jsonToVar(const String *json);
VariantList *jsonToVarLst(const String *json);

const String *jsonFromBool(bool value);
String *jsonFromInt(int number);
String *jsonFromInt64(int64_t number);
String *jsonFromKv(const KeyValue *kv);
String *jsonFromStr(const String *string);
String *jsonFromUInt(unsigned int number);
String *jsonFromUInt64(uint64_t number);
String *jsonFromVar(const Variant *var);

#endif

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