Skip to content

Commit 15cd9a3

Browse files
peterepetere
committed
jsonapi: Use const char *
Apply const qualifiers to char * arguments and fields throughout the jsonapi. This allows the top-level APIs such as pg_parse_json_incremental() to declare their input argument as const. It also reduces the number of unconstify() calls. Reviewed-by: Andrew Dunstan <andrew@dunslane.net> Discussion: https://www.postgresql.org/message-id/flat/f732b014-f614-4600-a437-dba5a2c3738b%40eisentraut.org
1 parent 0b06bf9 commit 15cd9a3

File tree

3 files changed

+41
-38
lines changed

3 files changed

+41
-38
lines changed

‎src/backend/utils/adt/jsonfuncs.c‎

Lines changed: 21 additions & 18 deletions
Original file line numberDiff line numberDiff line change
@@ -86,7 +86,7 @@ typedef struct GetState
8686
{
8787
JsonLexContext *lex;
8888
text *tresult;
89-
char *result_start;
89+
const char *result_start;
9090
bool normalize_results;
9191
bool next_scalar;
9292
int npath; /* length of each path-related array */
@@ -111,7 +111,7 @@ typedef struct EachState
111111
Tuplestorestate *tuple_store;
112112
TupleDesc ret_tdesc;
113113
MemoryContext tmp_cxt;
114-
char *result_start;
114+
const char *result_start;
115115
bool normalize_results;
116116
bool next_scalar;
117117
char *normalized_scalar;
@@ -125,7 +125,7 @@ typedef struct ElementsState
125125
Tuplestorestate *tuple_store;
126126
TupleDesc ret_tdesc;
127127
MemoryContext tmp_cxt;
128-
char *result_start;
128+
const char *result_start;
129129
bool normalize_results;
130130
bool next_scalar;
131131
char *normalized_scalar;
@@ -138,7 +138,7 @@ typedef struct JHashState
138138
const char *function_name;
139139
HTAB *hash;
140140
char *saved_scalar;
141-
char *save_json_start;
141+
const char *save_json_start;
142142
JsonTokenType saved_token_type;
143143
} JHashState;
144144

@@ -247,7 +247,7 @@ typedef struct PopulateRecordsetState
247247
const char *function_name;
248248
HTAB *json_hash;
249249
char *saved_scalar;
250-
char *save_json_start;
250+
const char *save_json_start;
251251
JsonTokenType saved_token_type;
252252
Tuplestorestate *tuple_store;
253253
HeapTupleHeader rec;
@@ -273,7 +273,7 @@ typedef struct PopulateArrayState
273273
{
274274
JsonLexContext *lex; /* json lexer */
275275
PopulateArrayContext *ctx; /* context */
276-
char *element_start; /* start of the current array element */
276+
const char *element_start; /* start of the current array element */
277277
char *element_scalar; /* current array element token if it is a
278278
* scalar */
279279
JsonTokenType element_type; /* current array element type */
@@ -295,7 +295,7 @@ typedef struct JsValue
295295
{
296296
struct
297297
{
298-
char *str; /* json string */
298+
const char *str; /* json string */
299299
int len; /* json string length or -1 if null-terminated */
300300
JsonTokenType type; /* json type */
301301
} json; /* json value */
@@ -390,7 +390,7 @@ static JsonParseErrorType elements_array_element_end(void *state, bool isnull);
390390
static JsonParseErrorType elements_scalar(void *state, char *token, JsonTokenType tokentype);
391391

392392
/* turn a json object into a hash table */
393-
static HTAB *get_json_object_as_hash(char *json, int len, const char *funcname,
393+
static HTAB *get_json_object_as_hash(const char *json, int len, const char *funcname,
394394
Node *escontext);
395395

396396
/* semantic actions for populate_array_json */
@@ -456,7 +456,7 @@ static Datum populate_record_field(ColumnIOData *col, Oid typid, int32 typmod,
456456
static RecordIOData *allocate_record_info(MemoryContext mcxt, int ncolumns);
457457
static bool JsObjectGetField(JsObject *obj, char *field, JsValue *jsv);
458458
static void populate_recordset_record(PopulateRecordsetState *state, JsObject *obj);
459-
static bool populate_array_json(PopulateArrayContext *ctx, char *json, int len);
459+
static bool populate_array_json(PopulateArrayContext *ctx, const char *json, int len);
460460
static bool populate_array_dim_jsonb(PopulateArrayContext *ctx, JsonbValue *jbv,
461461
int ndim);
462462
static void populate_array_report_expected_array(PopulateArrayContext *ctx, int ndim);
@@ -1181,7 +1181,7 @@ get_object_end(void *state)
11811181
if (lex_level == 0 && _state->npath == 0)
11821182
{
11831183
/* Special case: return the entire object */
1184-
char *start = _state->result_start;
1184+
const char *start = _state->result_start;
11851185
int len = _state->lex->prev_token_terminator - start;
11861186

11871187
_state->tresult = cstring_to_text_with_len(start, len);
@@ -1275,7 +1275,7 @@ get_object_field_end(void *state, char *fname, bool isnull)
12751275
_state->tresult = (text *) NULL;
12761276
else
12771277
{
1278-
char *start = _state->result_start;
1278+
const char *start = _state->result_start;
12791279
int len = _state->lex->prev_token_terminator - start;
12801280

12811281
_state->tresult = cstring_to_text_with_len(start, len);
@@ -1337,7 +1337,7 @@ get_array_end(void *state)
13371337
if (lex_level == 0 && _state->npath == 0)
13381338
{
13391339
/* Special case: return the entire array */
1340-
char *start = _state->result_start;
1340+
const char *start = _state->result_start;
13411341
int len = _state->lex->prev_token_terminator - start;
13421342

13431343
_state->tresult = cstring_to_text_with_len(start, len);
@@ -1426,7 +1426,7 @@ get_array_element_end(void *state, bool isnull)
14261426
_state->tresult = (text *) NULL;
14271427
else
14281428
{
1429-
char *start = _state->result_start;
1429+
const char *start = _state->result_start;
14301430
int len = _state->lex->prev_token_terminator - start;
14311431

14321432
_state->tresult = cstring_to_text_with_len(start, len);
@@ -1463,7 +1463,7 @@ get_scalar(void *state, char *token, JsonTokenType tokentype)
14631463
* scalar token, but not whitespace before it. Probably not worth
14641464
* doing our own space-skipping to avoid that.
14651465
*/
1466-
char *start = _state->lex->input;
1466+
const char *start = _state->lex->input;
14671467
int len = _state->lex->prev_token_terminator - start;
14681468

14691469
_state->tresult = cstring_to_text_with_len(start, len);
@@ -2782,7 +2782,7 @@ populate_array_scalar(void *_state, char *token, JsonTokenType tokentype)
27822782
* Returns false if an error occurs when parsing.
27832783
*/
27842784
static bool
2785-
populate_array_json(PopulateArrayContext *ctx, char *json, int len)
2785+
populate_array_json(PopulateArrayContext *ctx, const char *json, int len)
27862786
{
27872787
PopulateArrayState state;
27882788
JsonSemAction sem;
@@ -3123,7 +3123,7 @@ populate_scalar(ScalarIOData *io, Oid typid, int32 typmod, JsValue *jsv,
31233123
{
31243124
Datum res;
31253125
char *str = NULL;
3126-
char *json = NULL;
3126+
const char *json = NULL;
31273127

31283128
if (jsv->is_json)
31293129
{
@@ -3139,7 +3139,10 @@ populate_scalar(ScalarIOData *io, Oid typid, int32 typmod, JsValue *jsv,
31393139
str[len] = '\0';
31403140
}
31413141
else
3142-
str = json; /* string is already null-terminated */
3142+
{
3143+
/* string is already null-terminated */
3144+
str = unconstify(char *, json);
3145+
}
31433146

31443147
/* If converting to json/jsonb, make string into valid JSON literal */
31453148
if ((typid == JSONOID || typid == JSONBOID) &&
@@ -3784,7 +3787,7 @@ populate_record_worker(FunctionCallInfo fcinfo, const char *funcname,
37843787
* Returns the hash table if the json is parsed successfully, NULL otherwise.
37853788
*/
37863789
static HTAB *
3787-
get_json_object_as_hash(char *json, int len, const char *funcname,
3790+
get_json_object_as_hash(const char *json, int len, const char *funcname,
37883791
Node *escontext)
37893792
{
37903793
HASHCTL ctl;

‎src/common/jsonapi.c‎

Lines changed: 13 additions & 13 deletions
Original file line numberDiff line numberDiff line change
@@ -211,7 +211,7 @@ static td_entry td_parser_table[JSON_NUM_NONTERMINALS][JSON_NUM_TERMINALS] =
211211
static char JSON_PROD_GOAL[] = {JSON_TOKEN_END, JSON_NT_JSON, 0};
212212

213213
static inline JsonParseErrorType json_lex_string(JsonLexContext *lex);
214-
static inline JsonParseErrorType json_lex_number(JsonLexContext *lex, char *s,
214+
static inline JsonParseErrorType json_lex_number(JsonLexContext *lex, const char *s,
215215
bool *num_err, size_t *total_len);
216216
static inline JsonParseErrorType parse_scalar(JsonLexContext *lex, JsonSemAction *sem);
217217
static JsonParseErrorType parse_object_field(JsonLexContext *lex, JsonSemAction *sem);
@@ -290,12 +290,12 @@ IsValidJsonNumber(const char *str, size_t len)
290290
*/
291291
if (*str == '-')
292292
{
293-
dummy_lex.input = unconstify(char *, str) + 1;
293+
dummy_lex.input = str + 1;
294294
dummy_lex.input_length = len - 1;
295295
}
296296
else
297297
{
298-
dummy_lex.input = unconstify(char *, str);
298+
dummy_lex.input = str;
299299
dummy_lex.input_length = len;
300300
}
301301

@@ -323,7 +323,7 @@ IsValidJsonNumber(const char *str, size_t len)
323323
* cleanup.
324324
*/
325325
JsonLexContext *
326-
makeJsonLexContextCstringLen(JsonLexContext *lex, char *json,
326+
makeJsonLexContextCstringLen(JsonLexContext *lex, const char *json,
327327
size_t len, int encoding, bool need_escapes)
328328
{
329329
if (lex == NULL)
@@ -649,7 +649,7 @@ json_count_array_elements(JsonLexContext *lex, int *elements)
649649
JsonParseErrorType
650650
pg_parse_json_incremental(JsonLexContext *lex,
651651
JsonSemAction *sem,
652-
char *json,
652+
const char *json,
653653
size_t len,
654654
bool is_last)
655655
{
@@ -1308,8 +1308,8 @@ parse_array(JsonLexContext *lex, JsonSemAction *sem)
13081308
JsonParseErrorType
13091309
json_lex(JsonLexContext *lex)
13101310
{
1311-
char *s;
1312-
char *const end = lex->input + lex->input_length;
1311+
const char *s;
1312+
const char *const end = lex->input + lex->input_length;
13131313
JsonParseErrorType result;
13141314

13151315
if (lex->incremental && lex->inc_state->partial_completed)
@@ -1593,7 +1593,7 @@ json_lex(JsonLexContext *lex)
15931593
break;
15941594
default:
15951595
{
1596-
char *p;
1596+
const char *p;
15971597

15981598
/*
15991599
* We're not dealing with a string, number, legal
@@ -1671,8 +1671,8 @@ json_lex(JsonLexContext *lex)
16711671
static inline JsonParseErrorType
16721672
json_lex_string(JsonLexContext *lex)
16731673
{
1674-
char *s;
1675-
char *const end = lex->input + lex->input_length;
1674+
const char *s;
1675+
const char *const end = lex->input + lex->input_length;
16761676
int hi_surrogate = -1;
16771677

16781678
/* Convenience macros for error exits */
@@ -1689,7 +1689,7 @@ json_lex_string(JsonLexContext *lex)
16891689
} while (0)
16901690
#define FAIL_AT_CHAR_END(code) \
16911691
do { \
1692-
char *term = s + pg_encoding_mblen(lex->input_encoding, s); \
1692+
const char *term = s + pg_encoding_mblen(lex->input_encoding, s); \
16931693
lex->token_terminator = (term <= end) ? term : end; \
16941694
return code; \
16951695
} while (0)
@@ -1854,7 +1854,7 @@ json_lex_string(JsonLexContext *lex)
18541854
}
18551855
else
18561856
{
1857-
char *p = s;
1857+
const char *p = s;
18581858

18591859
if (hi_surrogate != -1)
18601860
FAIL_AT_CHAR_END(JSON_UNICODE_LOW_SURROGATE);
@@ -1940,7 +1940,7 @@ json_lex_string(JsonLexContext *lex)
19401940
* the distance from lex->input to the token end+1 is returned to *total_len.
19411941
*/
19421942
static inline JsonParseErrorType
1943-
json_lex_number(JsonLexContext *lex, char *s,
1943+
json_lex_number(JsonLexContext *lex, const char *s,
19441944
bool *num_err, size_t *total_len)
19451945
{
19461946
bool error = false;

‎src/include/common/jsonapi.h‎

Lines changed: 7 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -88,18 +88,18 @@ typedef struct JsonIncrementalState JsonIncrementalState;
8888
#define JSONLEX_FREE_STRVAL (1 << 1)
8989
typedef struct JsonLexContext
9090
{
91-
char *input;
91+
const char *input;
9292
size_t input_length;
9393
int input_encoding;
94-
char *token_start;
95-
char *token_terminator;
96-
char *prev_token_terminator;
94+
const char *token_start;
95+
const char *token_terminator;
96+
const char *prev_token_terminator;
9797
bool incremental;
9898
JsonTokenType token_type;
9999
int lex_level;
100100
bits32 flags;
101101
int line_number; /* line number, starting from 1 */
102-
char *line_start; /* where that line starts within input */
102+
const char *line_start; /* where that line starts within input */
103103
JsonParserStack *pstack;
104104
JsonIncrementalState *inc_state;
105105
StringInfo strval;
@@ -157,7 +157,7 @@ extern JsonParseErrorType pg_parse_json(JsonLexContext *lex,
157157

158158
extern JsonParseErrorType pg_parse_json_incremental(JsonLexContext *lex,
159159
JsonSemAction *sem,
160-
char *json,
160+
const char *json,
161161
size_t len,
162162
bool is_last);
163163

@@ -192,7 +192,7 @@ extern JsonParseErrorType json_count_array_elements(JsonLexContext *lex,
192192
* cleanup.
193193
*/
194194
extern JsonLexContext *makeJsonLexContextCstringLen(JsonLexContext *lex,
195-
char *json,
195+
const char *json,
196196
size_t len,
197197
int encoding,
198198
bool need_escapes);

0 commit comments

Comments
 (0)