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-rw-r--r--src/common/jsonapi.c102
1 files changed, 94 insertions, 8 deletions
diff --git a/src/common/jsonapi.c b/src/common/jsonapi.c
index ca4ecd571ef..0e2a82ad7a1 100644
--- a/src/common/jsonapi.c
+++ b/src/common/jsonapi.c
@@ -161,6 +161,7 @@ struct JsonParserStack
*/
struct JsonIncrementalState
{
+ bool started;
bool is_last_chunk;
bool partial_completed;
jsonapi_StrValType partial_token;
@@ -280,6 +281,7 @@ static JsonParseErrorType parse_array_element(JsonLexContext *lex, const JsonSem
static JsonParseErrorType parse_array(JsonLexContext *lex, const JsonSemAction *sem);
static JsonParseErrorType report_parse_error(JsonParseContext ctx, JsonLexContext *lex);
static bool allocate_incremental_state(JsonLexContext *lex);
+static inline void set_fname(JsonLexContext *lex, char *fname);
/* the null action object used for pure validation */
const JsonSemAction nullSemAction =
@@ -437,7 +439,7 @@ allocate_incremental_state(JsonLexContext *lex)
*fnull;
lex->inc_state = ALLOC0(sizeof(JsonIncrementalState));
- pstack = ALLOC(sizeof(JsonParserStack));
+ pstack = ALLOC0(sizeof(JsonParserStack));
prediction = ALLOC(JS_STACK_CHUNK_SIZE * JS_MAX_PROD_LEN);
fnames = ALLOC(JS_STACK_CHUNK_SIZE * sizeof(char *));
fnull = ALLOC(JS_STACK_CHUNK_SIZE * sizeof(bool));
@@ -464,10 +466,17 @@ allocate_incremental_state(JsonLexContext *lex)
lex->pstack = pstack;
lex->pstack->stack_size = JS_STACK_CHUNK_SIZE;
lex->pstack->prediction = prediction;
- lex->pstack->pred_index = 0;
lex->pstack->fnames = fnames;
lex->pstack->fnull = fnull;
+ /*
+ * fnames between 0 and lex_level must always be defined so that
+ * freeJsonLexContext() can handle them safely. inc/dec_lex_level() handle
+ * the rest.
+ */
+ Assert(lex->lex_level == 0);
+ lex->pstack->fnames[0] = NULL;
+
lex->incremental = true;
return true;
}
@@ -530,6 +539,25 @@ makeJsonLexContextIncremental(JsonLexContext *lex, int encoding,
return lex;
}
+void
+setJsonLexContextOwnsTokens(JsonLexContext *lex, bool owned_by_context)
+{
+ if (lex->incremental && lex->inc_state->started)
+ {
+ /*
+ * Switching this flag after parsing has already started is a
+ * programming error.
+ */
+ Assert(false);
+ return;
+ }
+
+ if (owned_by_context)
+ lex->flags |= JSONLEX_CTX_OWNS_TOKENS;
+ else
+ lex->flags &= ~JSONLEX_CTX_OWNS_TOKENS;
+}
+
static inline bool
inc_lex_level(JsonLexContext *lex)
{
@@ -569,12 +597,23 @@ inc_lex_level(JsonLexContext *lex)
}
lex->lex_level += 1;
+
+ if (lex->incremental)
+ {
+ /*
+ * Ensure freeJsonLexContext() remains safe even if no fname is
+ * assigned at this level.
+ */
+ lex->pstack->fnames[lex->lex_level] = NULL;
+ }
+
return true;
}
static inline void
dec_lex_level(JsonLexContext *lex)
{
+ set_fname(lex, NULL); /* free the current level's fname, if needed */
lex->lex_level -= 1;
}
@@ -608,6 +647,15 @@ have_prediction(JsonParserStack *pstack)
static inline void
set_fname(JsonLexContext *lex, char *fname)
{
+ if (lex->flags & JSONLEX_CTX_OWNS_TOKENS)
+ {
+ /*
+ * Don't leak prior fnames. If one hasn't been assigned yet,
+ * inc_lex_level ensured that it's NULL (and therefore safe to free).
+ */
+ FREE(lex->pstack->fnames[lex->lex_level]);
+ }
+
lex->pstack->fnames[lex->lex_level] = fname;
}
@@ -655,8 +703,19 @@ freeJsonLexContext(JsonLexContext *lex)
jsonapi_termStringInfo(&lex->inc_state->partial_token);
FREE(lex->inc_state);
FREE(lex->pstack->prediction);
+
+ if (lex->flags & JSONLEX_CTX_OWNS_TOKENS)
+ {
+ int i;
+
+ /* Clean up any tokens that were left behind. */
+ for (i = 0; i <= lex->lex_level; i++)
+ FREE(lex->pstack->fnames[i]);
+ }
+
FREE(lex->pstack->fnames);
FREE(lex->pstack->fnull);
+ FREE(lex->pstack->scalar_val);
FREE(lex->pstack);
}
@@ -826,6 +885,7 @@ pg_parse_json_incremental(JsonLexContext *lex,
lex->input = lex->token_terminator = lex->line_start = json;
lex->input_length = len;
lex->inc_state->is_last_chunk = is_last;
+ lex->inc_state->started = true;
/* get the initial token */
result = json_lex(lex);
@@ -1086,6 +1146,17 @@ pg_parse_json_incremental(JsonLexContext *lex,
if (sfunc != NULL)
{
result = (*sfunc) (sem->semstate, pstack->scalar_val, pstack->scalar_tok);
+
+ /*
+ * Either ownership of the token passed to the
+ * callback, or we need to free it now. Either
+ * way, clear our pointer to it so it doesn't get
+ * freed in the future.
+ */
+ if (lex->flags & JSONLEX_CTX_OWNS_TOKENS)
+ FREE(pstack->scalar_val);
+ pstack->scalar_val = NULL;
+
if (result != JSON_SUCCESS)
return result;
}
@@ -1221,11 +1292,17 @@ parse_scalar(JsonLexContext *lex, const JsonSemAction *sem)
/* consume the token */
result = json_lex(lex);
if (result != JSON_SUCCESS)
+ {
+ FREE(val);
return result;
+ }
- /* invoke the callback */
+ /* invoke the callback, which may take ownership of val */
result = (*sfunc) (sem->semstate, val, tok);
+ if (lex->flags & JSONLEX_CTX_OWNS_TOKENS)
+ FREE(val);
+
return result;
}
@@ -1238,7 +1315,7 @@ parse_object_field(JsonLexContext *lex, const JsonSemAction *sem)
* generally call a field name a "key".
*/
- char *fname = NULL; /* keep compiler quiet */
+ char *fname = NULL;
json_ofield_action ostart = sem->object_field_start;
json_ofield_action oend = sem->object_field_end;
bool isnull;
@@ -1255,11 +1332,17 @@ parse_object_field(JsonLexContext *lex, const JsonSemAction *sem)
}
result = json_lex(lex);
if (result != JSON_SUCCESS)
+ {
+ FREE(fname);
return result;
+ }
result = lex_expect(JSON_PARSE_OBJECT_LABEL, lex, JSON_TOKEN_COLON);
if (result != JSON_SUCCESS)
+ {
+ FREE(fname);
return result;
+ }
tok = lex_peek(lex);
isnull = tok == JSON_TOKEN_NULL;
@@ -1268,7 +1351,7 @@ parse_object_field(JsonLexContext *lex, const JsonSemAction *sem)
{
result = (*ostart) (sem->semstate, fname, isnull);
if (result != JSON_SUCCESS)
- return result;
+ goto ofield_cleanup;
}
switch (tok)
@@ -1283,16 +1366,19 @@ parse_object_field(JsonLexContext *lex, const JsonSemAction *sem)
result = parse_scalar(lex, sem);
}
if (result != JSON_SUCCESS)
- return result;
+ goto ofield_cleanup;
if (oend != NULL)
{
result = (*oend) (sem->semstate, fname, isnull);
if (result != JSON_SUCCESS)
- return result;
+ goto ofield_cleanup;
}
- return JSON_SUCCESS;
+ofield_cleanup:
+ if (lex->flags & JSONLEX_CTX_OWNS_TOKENS)
+ FREE(fname);
+ return result;
}
static JsonParseErrorType
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-22 13:24:33 +0000