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authorRobert Haas2020-01-27 16:03:21 +0000
committerRobert Haas2020-01-27 16:04:51 +0000
commit1f3a021730be98b880d94cabbe21de7e4d8136f5 (patch)
treea1eacb3d158bef0a800bb751906bc2640e5eb908
parent3e4818e9dd5be294d97ca67012528cb1c0b0ccaa (diff)
Adjust pg_parse_json() so that it does not directly ereport().
Instead, it now returns a value indicating either success or the type of error which occurred. The old behavior is still available by calling pg_parse_json_or_ereport(). If the new interface is used, an error can be thrown by passing the return value of pg_parse_json() to json_ereport_error(). pg_parse_json() can still elog() in can't-happen cases, but it seems like that issue is best handled separately. Adjust json_lex() and json_count_array_elements() to return an error code, too. This is all in preparation for making the backend's json parser available to frontend code. Reviewed and/or tested by Mark Dilger and Andrew Dunstan. Discussion: http://postgr.es/m/CA+TgmoYfOXhd27MUDGioVh6QtpD0C1K-f6ObSA10AWiHBAL5bA@mail.gmail.com
-rw-r--r--src/backend/utils/adt/json.c9
-rw-r--r--src/backend/utils/adt/jsonapi.c537
-rw-r--r--src/backend/utils/adt/jsonb.c4
-rw-r--r--src/backend/utils/adt/jsonfuncs.c29
-rw-r--r--src/include/utils/jsonapi.h46
5 files changed, 342 insertions, 283 deletions
diff --git a/src/backend/utils/adt/json.c b/src/backend/utils/adt/json.c
index 4be16b5c20..e73a60ece8 100644
--- a/src/backend/utils/adt/json.c
+++ b/src/backend/utils/adt/json.c
@@ -81,7 +81,7 @@ json_in(PG_FUNCTION_ARGS)
/* validate it */
lex = makeJsonLexContext(result, false);
- pg_parse_json(lex, &nullSemAction);
+ pg_parse_json_or_ereport(lex, &nullSemAction);
/* Internal representation is the same as text, for now */
PG_RETURN_TEXT_P(result);
@@ -128,7 +128,7 @@ json_recv(PG_FUNCTION_ARGS)
/* Validate it. */
lex = makeJsonLexContextCstringLen(str, nbytes, false);
- pg_parse_json(lex, &nullSemAction);
+ pg_parse_json_or_ereport(lex, &nullSemAction);
PG_RETURN_TEXT_P(cstring_to_text_with_len(str, nbytes));
}
@@ -1337,12 +1337,15 @@ json_typeof(PG_FUNCTION_ARGS)
JsonLexContext *lex;
JsonTokenType tok;
char *type;
+ JsonParseErrorType result;
json = PG_GETARG_TEXT_PP(0);
lex = makeJsonLexContext(json, false);
/* Lex exactly one token from the input and check its type. */
- json_lex(lex);
+ result = json_lex(lex);
+ if (result != JSON_SUCCESS)
+ json_ereport_error(result, lex);
tok = lex->token_type;
switch (tok)
{
diff --git a/src/backend/utils/adt/jsonapi.c b/src/backend/utils/adt/jsonapi.c
index 9e14306b6f..129fbd65d5 100644
--- a/src/backend/utils/adt/jsonapi.c
+++ b/src/backend/utils/adt/jsonapi.c
@@ -35,18 +35,17 @@ typedef enum /* contexts of JSON parser */
JSON_PARSE_END /* saw the end of a document, expect nothing */
} JsonParseContext;
-static inline void json_lex_string(JsonLexContext *lex);
-static inline void json_lex_number(JsonLexContext *lex, char *s,
+static inline JsonParseErrorType json_lex_string(JsonLexContext *lex);
+static inline JsonParseErrorType json_lex_number(JsonLexContext *lex, char *s,
bool *num_err, int *total_len);
-static inline void parse_scalar(JsonLexContext *lex, JsonSemAction *sem);
-static void parse_object_field(JsonLexContext *lex, JsonSemAction *sem);
-static void parse_object(JsonLexContext *lex, JsonSemAction *sem);
-static void parse_array_element(JsonLexContext *lex, JsonSemAction *sem);
-static void parse_array(JsonLexContext *lex, JsonSemAction *sem);
-static void report_parse_error(JsonParseContext ctx, JsonLexContext *lex) pg_attribute_noreturn();
-static void report_invalid_token(JsonLexContext *lex) pg_attribute_noreturn();
+static inline JsonParseErrorType parse_scalar(JsonLexContext *lex, JsonSemAction *sem);
+static JsonParseErrorType parse_object_field(JsonLexContext *lex, JsonSemAction *sem);
+static JsonParseErrorType parse_object(JsonLexContext *lex, JsonSemAction *sem);
+static JsonParseErrorType parse_array_element(JsonLexContext *lex, JsonSemAction *sem);
+static JsonParseErrorType parse_array(JsonLexContext *lex, JsonSemAction *sem);
+static JsonParseErrorType report_parse_error(JsonParseContext ctx, JsonLexContext *lex);
static int report_json_context(JsonLexContext *lex);
-static char *extract_mb_char(char *s);
+static char *extract_token(JsonLexContext *lex);
/* the null action object used for pure validation */
JsonSemAction nullSemAction =
@@ -74,13 +73,13 @@ lex_peek(JsonLexContext *lex)
* move the lexer to the next token if the current look_ahead token matches
* the parameter token. Otherwise, report an error.
*/
-static inline void
+static inline JsonParseErrorType
lex_expect(JsonParseContext ctx, JsonLexContext *lex, JsonTokenType token)
{
if (lex_peek(lex) == token)
- json_lex(lex);
+ return json_lex(lex);
else
- report_parse_error(ctx, lex);
+ return report_parse_error(ctx, lex);
}
/* chars to consider as part of an alphanumeric token */
@@ -171,13 +170,16 @@ makeJsonLexContextCstringLen(char *json, int len, bool need_escapes)
* action routines to be called at appropriate spots during parsing, and a
* pointer to a state object to be passed to those routines.
*/
-void
+JsonParseErrorType
pg_parse_json(JsonLexContext *lex, JsonSemAction *sem)
{
JsonTokenType tok;
+ JsonParseErrorType result;
/* get the initial token */
- json_lex(lex);
+ result = json_lex(lex);
+ if (result != JSON_SUCCESS)
+ return result;
tok = lex_peek(lex);
@@ -185,17 +187,36 @@ pg_parse_json(JsonLexContext *lex, JsonSemAction *sem)
switch (tok)
{
case JSON_TOKEN_OBJECT_START:
- parse_object(lex, sem);
+ result = parse_object(lex, sem);
break;
case JSON_TOKEN_ARRAY_START:
- parse_array(lex, sem);
+ result = parse_array(lex, sem);
break;
default:
- parse_scalar(lex, sem); /* json can be a bare scalar */
+ result = parse_scalar(lex, sem); /* json can be a bare scalar */
}
- lex_expect(JSON_PARSE_END, lex, JSON_TOKEN_END);
+ if (result == JSON_SUCCESS)
+ result = lex_expect(JSON_PARSE_END, lex, JSON_TOKEN_END);
+
+ return result;
+}
+
+/*
+ * pg_parse_json_or_ereport
+ *
+ * This fuction is like pg_parse_json, except that it does not return a
+ * JsonParseErrorType. Instead, in case of any failure, this function will
+ * ereport(ERROR).
+ */
+void
+pg_parse_json_or_ereport(JsonLexContext *lex, JsonSemAction *sem)
+{
+ JsonParseErrorType result;
+ result = pg_parse_json(lex, sem);
+ if (result != JSON_SUCCESS)
+ json_ereport_error(result, lex);
}
/*
@@ -206,11 +227,12 @@ pg_parse_json(JsonLexContext *lex, JsonSemAction *sem)
*
* Designed to be called from array_start routines.
*/
-int
-json_count_array_elements(JsonLexContext *lex)
+JsonParseErrorType
+json_count_array_elements(JsonLexContext *lex, int *elements)
{
JsonLexContext copylex;
int count;
+ JsonParseErrorType result;
/*
* It's safe to do this with a shallow copy because the lexical routines
@@ -222,21 +244,32 @@ json_count_array_elements(JsonLexContext *lex)
copylex.lex_level++;
count = 0;
- lex_expect(JSON_PARSE_ARRAY_START, &copylex, JSON_TOKEN_ARRAY_START);
+ result = lex_expect(JSON_PARSE_ARRAY_START, &copylex,
+ JSON_TOKEN_ARRAY_START);
+ if (result != JSON_SUCCESS)
+ return result;
if (lex_peek(&copylex) != JSON_TOKEN_ARRAY_END)
{
while (1)
{
count++;
- parse_array_element(&copylex, &nullSemAction);
+ result = parse_array_element(&copylex, &nullSemAction);
+ if (result != JSON_SUCCESS)
+ return result;
if (copylex.token_type != JSON_TOKEN_COMMA)
break;
- json_lex(&copylex);
+ result = json_lex(&copylex);
+ if (result != JSON_SUCCESS)
+ return result;
}
}
- lex_expect(JSON_PARSE_ARRAY_NEXT, &copylex, JSON_TOKEN_ARRAY_END);
+ result = lex_expect(JSON_PARSE_ARRAY_NEXT, &copylex,
+ JSON_TOKEN_ARRAY_END);
+ if (result != JSON_SUCCESS)
+ return result;
- return count;
+ *elements = count;
+ return JSON_SUCCESS;
}
/*
@@ -248,25 +281,23 @@ json_count_array_elements(JsonLexContext *lex)
* - object ( { } )
* - object field
*/
-static inline void
+static inline JsonParseErrorType
parse_scalar(JsonLexContext *lex, JsonSemAction *sem)
{
char *val = NULL;
json_scalar_action sfunc = sem->scalar;
JsonTokenType tok = lex_peek(lex);
+ JsonParseErrorType result;
/* a scalar must be a string, a number, true, false, or null */
if (tok != JSON_TOKEN_STRING && tok != JSON_TOKEN_NUMBER &&
tok != JSON_TOKEN_TRUE && tok != JSON_TOKEN_FALSE &&
tok != JSON_TOKEN_NULL)
- report_parse_error(JSON_PARSE_VALUE, lex);
+ return report_parse_error(JSON_PARSE_VALUE, lex);
/* if no semantic function, just consume the token */
if (sfunc == NULL)
- {
- json_lex(lex);
- return;
- }
+ return json_lex(lex);
/* extract the de-escaped string value, or the raw lexeme */
if (lex_peek(lex) == JSON_TOKEN_STRING)
@@ -284,13 +315,17 @@ parse_scalar(JsonLexContext *lex, JsonSemAction *sem)
}
/* consume the token */
- json_lex(lex);
+ result = json_lex(lex);
+ if (result != JSON_SUCCESS)
+ return result;
/* invoke the callback */
(*sfunc) (sem->semstate, val, tok);
+
+ return JSON_SUCCESS;
}
-static void
+static JsonParseErrorType
parse_object_field(JsonLexContext *lex, JsonSemAction *sem)
{
/*
@@ -304,14 +339,19 @@ parse_object_field(JsonLexContext *lex, JsonSemAction *sem)
json_ofield_action oend = sem->object_field_end;
bool isnull;
JsonTokenType tok;
+ JsonParseErrorType result;
if (lex_peek(lex) != JSON_TOKEN_STRING)
- report_parse_error(JSON_PARSE_STRING, lex);
+ return report_parse_error(JSON_PARSE_STRING, lex);
if ((ostart != NULL || oend != NULL) && lex->strval != NULL)
fname = pstrdup(lex->strval->data);
- json_lex(lex);
+ result = json_lex(lex);
+ if (result != JSON_SUCCESS)
+ return result;
- lex_expect(JSON_PARSE_OBJECT_LABEL, lex, JSON_TOKEN_COLON);
+ result = lex_expect(JSON_PARSE_OBJECT_LABEL, lex, JSON_TOKEN_COLON);
+ if (result != JSON_SUCCESS)
+ return result;
tok = lex_peek(lex);
isnull = tok == JSON_TOKEN_NULL;
@@ -322,20 +362,23 @@ parse_object_field(JsonLexContext *lex, JsonSemAction *sem)
switch (tok)
{
case JSON_TOKEN_OBJECT_START:
- parse_object(lex, sem);
+ result = parse_object(lex, sem);
break;
case JSON_TOKEN_ARRAY_START:
- parse_array(lex, sem);
+ result = parse_array(lex, sem);
break;
default:
- parse_scalar(lex, sem);
+ result = parse_scalar(lex, sem);
}
+ if (result != JSON_SUCCESS)
+ return result;
if (oend != NULL)
(*oend) (sem->semstate, fname, isnull);
+ return JSON_SUCCESS;
}
-static void
+static JsonParseErrorType
parse_object(JsonLexContext *lex, JsonSemAction *sem)
{
/*
@@ -345,6 +388,7 @@ parse_object(JsonLexContext *lex, JsonSemAction *sem)
json_struct_action ostart = sem->object_start;
json_struct_action oend = sem->object_end;
JsonTokenType tok;
+ JsonParseErrorType result;
check_stack_depth();
@@ -360,40 +404,51 @@ parse_object(JsonLexContext *lex, JsonSemAction *sem)
lex->lex_level++;
Assert(lex_peek(lex) == JSON_TOKEN_OBJECT_START);
- json_lex(lex);
+ result = json_lex(lex);
+ if (result != JSON_SUCCESS)
+ return result;
tok = lex_peek(lex);
switch (tok)
{
case JSON_TOKEN_STRING:
- parse_object_field(lex, sem);
- while (lex_peek(lex) == JSON_TOKEN_COMMA)
+ result = parse_object_field(lex, sem);
+ while (result == JSON_SUCCESS && lex_peek(lex) == JSON_TOKEN_COMMA)
{
- json_lex(lex);
- parse_object_field(lex, sem);
+ result = json_lex(lex);
+ if (result != JSON_SUCCESS)
+ break;
+ result = parse_object_field(lex, sem);
}
break;
case JSON_TOKEN_OBJECT_END:
break;
default:
/* case of an invalid initial token inside the object */
- report_parse_error(JSON_PARSE_OBJECT_START, lex);
+ result = report_parse_error(JSON_PARSE_OBJECT_START, lex);
}
+ if (result != JSON_SUCCESS)
+ return result;
- lex_expect(JSON_PARSE_OBJECT_NEXT, lex, JSON_TOKEN_OBJECT_END);
+ result = lex_expect(JSON_PARSE_OBJECT_NEXT, lex, JSON_TOKEN_OBJECT_END);
+ if (result != JSON_SUCCESS)
+ return result;
lex->lex_level--;
if (oend != NULL)
(*oend) (sem->semstate);
+
+ return JSON_SUCCESS;
}
-static void
+static JsonParseErrorType
parse_array_element(JsonLexContext *lex, JsonSemAction *sem)
{
json_aelem_action astart = sem->array_element_start;
json_aelem_action aend = sem->array_element_end;
JsonTokenType tok = lex_peek(lex);
+ JsonParseErrorType result;
bool isnull;
@@ -406,20 +461,25 @@ parse_array_element(JsonLexContext *lex, JsonSemAction *sem)
switch (tok)
{
case JSON_TOKEN_OBJECT_START:
- parse_object(lex, sem);
+ result = parse_object(lex, sem);
break;
case JSON_TOKEN_ARRAY_START:
- parse_array(lex, sem);
+ result = parse_array(lex, sem);
break;
default:
- parse_scalar(lex, sem);
+ result = parse_scalar(lex, sem);
}
+ if (result != JSON_SUCCESS)
+ return result;
+
if (aend != NULL)
(*aend) (sem->semstate, isnull);
+
+ return JSON_SUCCESS;
}
-static void
+static JsonParseErrorType
parse_array(JsonLexContext *lex, JsonSemAction *sem)
{
/*
@@ -428,6 +488,7 @@ parse_array(JsonLexContext *lex, JsonSemAction *sem)
*/
json_struct_action astart = sem->array_start;
json_struct_action aend = sem->array_end;
+ JsonParseErrorType result;
check_stack_depth();
@@ -442,35 +503,43 @@ parse_array(JsonLexContext *lex, JsonSemAction *sem)
*/
lex->lex_level++;
- lex_expect(JSON_PARSE_ARRAY_START, lex, JSON_TOKEN_ARRAY_START);
- if (lex_peek(lex) != JSON_TOKEN_ARRAY_END)
+ result = lex_expect(JSON_PARSE_ARRAY_START, lex, JSON_TOKEN_ARRAY_START);
+ if (result == JSON_SUCCESS && lex_peek(lex) != JSON_TOKEN_ARRAY_END)
{
+ result = parse_array_element(lex, sem);
- parse_array_element(lex, sem);
-
- while (lex_peek(lex) == JSON_TOKEN_COMMA)
+ while (result == JSON_SUCCESS && lex_peek(lex) == JSON_TOKEN_COMMA)
{
- json_lex(lex);