Add basic C JSON parser.

build/error.yaml

@@ -86,6 +86,9 @@ path-close: 97
 # Unable to get info for a file
 file-info: 98
 
+# Invalid JSON format.  Eventually this should be a child of format error and share the same code
+json-format: 99
+
 # This error should not be thrown directly -- it serves as a parent for the C errors
 runtime: 122
 

doc/xml/release.xml

@@ -53,6 +53,10 @@
                         <p>Add <code>uint64</code> variant type and supporting conversion functions.</p>
                     </release-item>
 
+                    <release-item>
+                        <p>Add basic C JSON parser.</p>
+                    </release-item>
+
                     <release-item>
                         <p>Allow <code>Buffer</code> object <quote>used size</quote> to be different than <quote>allocated size</quote>.  Add functions to manage used size and remaining size and update automatically when possible.</p>
                     </release-item>

lib/pgBackRest/Common/ExceptionAuto.pm

@@ -165,6 +165,8 @@ use constant ERROR_PATH_CLOSE                                       => 97;
 push @EXPORT, qw(ERROR_PATH_CLOSE);
 use constant ERROR_FILE_INFO                                        => 98;
 push @EXPORT, qw(ERROR_FILE_INFO);
+use constant ERROR_JSON_FORMAT                                      => 99;
+push @EXPORT, qw(ERROR_JSON_FORMAT);
 use constant ERROR_RUNTIME                                          => 122;
 push @EXPORT, qw(ERROR_RUNTIME);
 use constant ERROR_INVALID                                          => 123;

src/Makefile

@@ -214,6 +214,9 @@ common/type/buffer.o: common/type/buffer.c common/assert.h common/debug.h common
 common/type/convert.o: common/type/convert.c common/assert.h common/debug.h common/error.auto.h common/error.h common/logLevel.h common/stackTrace.h common/type/convert.h
 	$(CC) $(CFLAGS) -c common/type/convert.c -o common/type/convert.o
 
+common/type/json.o: common/type/json.c common/debug.h common/log.h common/logLevel.h common/stackTrace.h common/type/convert.h common/type/json.h common/type/keyValue.h common/type/variantList.h
+	$(CC) $(CFLAGS) -c common/type/json.c -o common/type/json.o
+
 common/type/keyValue.o: common/type/keyValue.c common/debug.h common/error.auto.h common/error.h common/logLevel.h common/memContext.h common/stackTrace.h common/type/buffer.h common/type/convert.h common/type/keyValue.h common/type/list.h common/type/string.h common/type/stringList.h common/type/variant.h common/type/variantList.h
 	$(CC) $(CFLAGS) -c common/type/keyValue.c -o common/type/keyValue.o
 

src/common/error.auto.c

@@ -80,6 +80,7 @@ ERROR_DEFINE( 95, CipherError, RuntimeError);
 ERROR_DEFINE( 96, ParamInvalidError, RuntimeError);
 ERROR_DEFINE( 97, PathCloseError, RuntimeError);
 ERROR_DEFINE( 98, FileInfoError, RuntimeError);
+ERROR_DEFINE( 99, JsonFormatError, RuntimeError);
 ERROR_DEFINE(122, RuntimeError, RuntimeError);
 ERROR_DEFINE(123, InvalidError, RuntimeError);
 ERROR_DEFINE(124, UnhandledError, RuntimeError);
@@ -163,6 +164,7 @@ static const ErrorType *errorTypeList[] =
     &ParamInvalidError,
     &PathCloseError,
     &FileInfoError,
+    &JsonFormatError,
     &RuntimeError,
     &InvalidError,
     &UnhandledError,

src/common/error.auto.h

@@ -82,6 +82,7 @@ ERROR_DECLARE(CipherError);
 ERROR_DECLARE(ParamInvalidError);
 ERROR_DECLARE(PathCloseError);
 ERROR_DECLARE(FileInfoError);
+ERROR_DECLARE(JsonFormatError);
 ERROR_DECLARE(RuntimeError);
 ERROR_DECLARE(InvalidError);
 ERROR_DECLARE(UnhandledError);

src/common/type/json.c

@@ -0,0 +1,111 @@
+/***********************************************************************************************************************************
+Convert JSON to/from KeyValue
+***********************************************************************************************************************************/
+#include <ctype.h>
+
+#include "common/debug.h"
+#include "common/log.h"
+#include "common/type/json.h"
+
+/***********************************************************************************************************************************
+Convert JSON to KeyValue object
+
+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.
+***********************************************************************************************************************************/
+KeyValue *jsonToKv(const String *json)
+{
+    FUNCTION_DEBUG_BEGIN(logLevelTrace);
+        FUNCTION_DEBUG_PARAM(STRING, json);
+
+        FUNCTION_TEST_ASSERT(json != NULL);
+    FUNCTION_DEBUG_END();
+
+    KeyValue *result = kvNew();
+
+    MEM_CONTEXT_TEMP_BEGIN()
+    {
+        // We'll examine the string byte by byte
+        const char *jsonC = strPtr(json);
+        unsigned int jsonPos = 0;
+
+        // Consume the initial delimiter
+        if (jsonC[jsonPos] == '[')
+            THROW(JsonFormatError, "arrays not supported");
+        else if (jsonC[jsonPos] != '{')
+            THROW_FMT(JsonFormatError, "expected '{' but found '%c'", jsonC[jsonPos]);
+
+        // Start parsing key/value pairs
+        do
+        {
+            Variant *value = NULL;
+
+            jsonPos++;
+
+            // Parse the key which should always be quoted
+            if (jsonC[jsonPos] != '"')
+                THROW_FMT(JsonFormatError, "expected '\"' but found '%c'", jsonC[jsonPos]);
+
+            unsigned int keyBeginPos = ++jsonPos;
+
+            while (jsonC[jsonPos] != '"' && jsonPos < strSize(json) - 1)
+                jsonPos++;
+
+            if (jsonC[jsonPos] != '"')
+                THROW_FMT(JsonFormatError, "expected '\"' but found '%c'", jsonC[jsonPos]);
+
+            String *key = strNewN(jsonC + keyBeginPos, jsonPos - keyBeginPos);
+
+            if (strSize(key) == 0)
+                THROW(JsonFormatError, "zero-length key not allowed");
+
+            if (jsonC[++jsonPos] != ':')
+                THROW_FMT(JsonFormatError, "expected ':' but found '%c'", jsonC[jsonPos]);
+
+            unsigned int valueBeginPos = ++jsonPos;
+
+            // The value appears to be a string
+            if (jsonC[jsonPos] == '"')
+            {
+                valueBeginPos++;
+                jsonPos++;
+
+                while (jsonC[jsonPos] != '"' && jsonPos < strSize(json) - 1)
+                    jsonPos++;
+
+                if (jsonC[jsonPos] != '"')
+                    THROW_FMT(JsonFormatError, "expected '\"' but found '%c'", jsonC[jsonPos]);
+
+                value = varNewStr(strNewN(jsonC + valueBeginPos, jsonPos - valueBeginPos));
+
+                jsonPos++;
+            }
+
+            // The value appears to be a number
+            else if (isdigit(jsonC[jsonPos]))
+            {
+                while (isdigit(jsonC[jsonPos]) && jsonPos < strSize(json) - 1)
+                    jsonPos++;
+
+                String *valueStr = strNewN(jsonC + valueBeginPos, jsonPos - valueBeginPos);
+
+                value = varNewUInt64(cvtZToUInt64(strPtr(valueStr)));
+            }
+
+            // Else not sure what it is.  Currently booleans and nulls will error.
+            else
+                THROW(JsonFormatError, "unknown value type");
+
+            kvPut(result, varNewStr(key), value);
+        }
+        while (jsonC[jsonPos] == ',');
+
+        // Look for end delimiter
+        if (jsonC[jsonPos] != '}')
+                THROW_FMT(JsonFormatError, "expected '}' but found '%c'", jsonC[jsonPos]);
+    }
+    MEM_CONTEXT_TEMP_END();
+
+    FUNCTION_DEBUG_RESULT(KEY_VALUE, result);
+}

src/common/type/json.h

@@ -0,0 +1,14 @@
+/***********************************************************************************************************************************
+Convert JSON to/from KeyValue
+***********************************************************************************************************************************/
+#ifndef COMMON_TYPE_JSON_H
+#define COMMON_TYPE_JSON_H
+
+#include "common/type/keyValue.h"
+
+/***********************************************************************************************************************************
+Functions
+***********************************************************************************************************************************/
+KeyValue *jsonToKv(const String *json);
+
+#endif

src/perl/embed.auto.c

@@ -5046,6 +5046,8 @@ static const EmbeddedModule embeddedModule[] =
             "push @EXPORT, qw(ERROR_PATH_CLOSE);\n"
             "use constant ERROR_FILE_INFO => 98;\n"
             "push @EXPORT, qw(ERROR_FILE_INFO);\n"
+            "use constant ERROR_JSON_FORMAT => 99;\n"
+            "push @EXPORT, qw(ERROR_JSON_FORMAT);\n"
             "use constant ERROR_RUNTIME => 122;\n"
             "push @EXPORT, qw(ERROR_RUNTIME);\n"
             "use constant ERROR_INVALID => 123;\n"

test/define.yaml

@@ -185,6 +185,13 @@ unit:
         coverage:
           common/type/variantList: full
 
+      # ----------------------------------------------------------------------------------------------------------------------------
+      - name: type-json
+        total: 1
+
+        coverage:
+          common/type/json: full
+
       # ----------------------------------------------------------------------------------------------------------------------------
       - name: type-key-value
         total: 2

test/src/module/common/typeJsonTest.c

@@ -0,0 +1,50 @@
+/***********************************************************************************************************************************
+Test Convert JSON to/from KeyValue
+***********************************************************************************************************************************/
+
+/***********************************************************************************************************************************
+Test Run
+***********************************************************************************************************************************/
+void
+testRun(void)
+{
+    FUNCTION_HARNESS_VOID();
+
+    // *****************************************************************************************************************************
+    if (testBegin("jsonToKv()"))
+    {
+        TEST_ERROR(jsonToKv(strNew("[")), JsonFormatError, "arrays not supported");
+        TEST_ERROR(jsonToKv(strNew("<")), JsonFormatError, "expected '{' but found '<'");
+        TEST_ERROR(jsonToKv(strNew("{>")), JsonFormatError, "expected '\"' but found '>'");
+        TEST_ERROR(jsonToKv(strNew("{\"\"")), JsonFormatError, "zero-length key not allowed");
+        TEST_ERROR(jsonToKv(strNew("{\"key1\"")), JsonFormatError, "expected ':' but found '");
+        TEST_ERROR(jsonToKv(strNew("{\"key1'")), JsonFormatError, "expected '\"' but found '''");
+        TEST_ERROR(jsonToKv(strNew("{\"key1\":t")), JsonFormatError, "unknown value type");
+        TEST_ERROR(jsonToKv(strNew("{\"key1\":123")), JsonFormatError, "expected '}' but found '3'");
+        TEST_ERROR(jsonToKv(strNew("{\"key1\":123>")), JsonFormatError, "expected '}' but found '>'");
+        TEST_ERROR(jsonToKv(strNew("{\"key1\":\"123'}")), JsonFormatError, "expected '\"' but found '}'");
+
+        // -------------------------------------------------------------------------------------------------------------------------
+        KeyValue *kv = NULL;
+
+        TEST_ASSIGN(kv, jsonToKv(strNew("{\"key1\":123}")), "single integer value");
+        TEST_RESULT_UINT(varUInt64(kvGet(kv, varNewStr(strNew("key1")))), 123, "  check integer");
+
+        TEST_ASSIGN(kv, jsonToKv(strNew("{\"key1\":\"value1\"}")), "single string value");
+        TEST_RESULT_STR(strPtr(varStr(kvGet(kv, varNewStr(strNew("key1"))))), "value1", "  check string");
+
+        TEST_ASSIGN(
+            kv,
+            jsonToKv(
+                strNew(
+                    "{\"db-catalog-version\":201409291,\"db-control-version\":942,\"db-system-id\":6116111691796124355,"
+                    "\"db-version\":\"9.4\"}")),
+            "multiple values");
+        TEST_RESULT_UINT(varUInt64(kvGet(kv, varNewStr(strNew("db-catalog-version")))), 201409291, "  check integer");
+        TEST_RESULT_UINT(varUInt64(kvGet(kv, varNewStr(strNew("db-control-version")))), 942, "  check integer");
+        TEST_RESULT_UINT(varUInt64(kvGet(kv, varNewStr(strNew("db-system-id")))), 6116111691796124355, "  check integer");
+        TEST_RESULT_STR(strPtr(varStr(kvGet(kv, varNewStr(strNew("db-version"))))), "9.4", "  check string");
+    }
+
+    FUNCTION_HARNESS_RESULT_VOID();
+}