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Add a prototype JSON parser.

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FossilOrigin-Name: 789ba487000aa73621a41d115ad5de455ea8ea31
This commit is contained in:
drh
2015-08-15 21:25:36 +00:00
parent bd0621b360
commit e9c37f32e5
3 changed files with 291 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files
ext/misc/json.c
+284 -18
View File
@@ -77,6 +77,7 @@
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>
#include <ctype.h>
/* Unsigned integer types */
typedef sqlite3_uint64 u64;
@@ -93,20 +94,41 @@ struct Json {
u64 nAlloc; /* Bytes of storage available in zBuf[] */
u64 nUsed; /* Bytes of zBuf[] currently used */
u8 bStatic; /* True if zBuf is static space */
u8 mallocFailed; /* True if an OOM has been encountered */
u8 oom; /* True if an OOM has been encountered */
char zSpace[100]; /* Initial static space */
};
/* JSONB type values
/* JSON type values
*/
#define JSONB_NULL 0
#define JSONB_TRUE 1
#define JSONB_FALSE 2
#define JSONB_INT 3
#define JSONB_REAL 4
#define JSONB_STRING 5
#define JSONB_ARRAY 6
#define JSONB_OBJECT 7
#define JSON_NULL 0
#define JSON_TRUE 1
#define JSON_FALSE 2
#define JSON_INT 3
#define JSON_REAL 4
#define JSON_STRING 5
#define JSON_ARRAY 6
#define JSON_OBJECT 7
/* A single node of parsed JSON
*/
typedef struct JsonNode JsonNode;
struct JsonNode {
u32 eType; /* One of the JSON_ type values */
u32 n; /* Bytes of content, or number of sub-nodes */
const char *zContent; /* Content for JSON_INT, JSON_REAL, or JSON_STRING */
};
/* A completely parsed JSON string
*/
typedef struct JsonParse JsonParse;
struct JsonParse {
u32 nNode; /* Number of slots of aNode[] used */
u32 nAlloc; /* Number of slots of aNode[] allocated */
JsonNode *aNode; /* Array of nodes containing the parse */
const char *zJson; /* Original JSON string */
u8 oom; /* Set to true if out of memory */
};
#if 0
/*
@@ -177,7 +199,7 @@ static void jsonZero(Json *p){
*/
static void jsonInit(Json *p, sqlite3_context *pCtx){
p->pCtx = pCtx;
p->mallocFailed = 0;
p->oom = 0;
jsonZero(p);
}
@@ -194,7 +216,7 @@ static void jsonReset(Json *p){
/* Report an out-of-memory (OOM) condition
*/
static void jsonOom(Json *p){
p->mallocFailed = 1;
p->oom = 1;
sqlite3_result_error_nomem(p->pCtx);
jsonReset(p);
}
@@ -206,7 +228,7 @@ static int jsonGrow(Json *p, u32 N){
u64 nTotal = N<p->nAlloc ? p->nAlloc*2 : p->nAlloc+N+100;
char *zNew;
if( p->bStatic ){
if( p->mallocFailed ) return SQLITE_NOMEM;
if( p->oom ) return SQLITE_NOMEM;
zNew = sqlite3_malloc64(nTotal);
if( zNew==0 ){
jsonOom(p);
@@ -235,6 +257,12 @@ static void jsonAppendRaw(Json *p, const char *zIn, u32 N){
p->nUsed += N;
}
/* Append the zero-terminated string zIn
*/
static void jsonAppend(Json *p, const char *zIn){
jsonAppendRaw(p, zIn, (u32)strlen(zIn));
}
/* Append the N-byte string in zIn to the end of the Json string
** under construction. Enclose the string in "..." and escape
** any double-quotes or backslash characters contained within the
@@ -343,7 +371,7 @@ static void jsonAppendVarint(Json *p, u64 X){
/* Make the JSON in p the result of the SQL function.
*/
static void jsonResult(Json *p){
if( p->mallocFailed==0 ){
if( p->oom==0 ){
sqlite3_result_text64(p->pCtx, p->zBuf, p->nUsed,
p->bStatic ? SQLITE_TRANSIENT : sqlite3_free,
SQLITE_UTF8);
@@ -355,7 +383,7 @@ static void jsonResult(Json *p){
/* Make the JSONB in p the result of the SQL function.
*/
static void jsonbResult(Json *p){
if( p->mallocFailed==0 ){
if( p->oom==0 ){
sqlite3_result_blob(p->pCtx, p->zBuf, p->nUsed,
p->bStatic ? SQLITE_TRANSIENT : sqlite3_free);
jsonZero(p);
@@ -428,7 +456,7 @@ static void jsonbArrayFunc(
for(i=0; i<argc; i++){
switch( sqlite3_value_type(argv[i]) ){
case SQLITE_NULL: {
jsonAppendVarint(&jx, JSONB_NULL);
jsonAppendVarint(&jx, JSON_NULL);
break;
}
case SQLITE_INTEGER:
@@ -441,7 +469,7 @@ static void jsonbArrayFunc(
case SQLITE_TEXT: {
const char *z = (const char*)sqlite3_value_text(argv[i]);
u32 n = (u32)sqlite3_value_bytes(argv[i]);
jsonAppendVarint(&jx, JSONB_STRING + 4*(u64)n);
jsonAppendVarint(&jx, JSON_STRING + 4*(u64)n);
jsonAppendString(&jx, z, n);
break;
}
@@ -452,7 +480,7 @@ static void jsonbArrayFunc(
}
}
}
if( jx.mallocFailed==0 ){
if( jx.oom==0 ){
jx.zBuf[0] = 251;
jsonPutInt32((unsigned char*)(jx.zBuf+1), jx.nUsed-5);
jsonbResult(&jx);
@@ -522,6 +550,243 @@ static void jsonObjectFunc(
jsonResult(&jx);
}
/*
** Create a new JsonNode instance based on the arguments and append that
** instance to the JsonParse. Return the index in pParse->aNode[] of the
** new node, or -1 if a memory allocation fails.
*/
static int jsonParseAddNode(
JsonParse *pParse, /* Append the node to this object */
u32 eType, /* Node type */
u32 n, /* Content size or sub-node count */
const char *zContent /* Content */
){
JsonNode *p;
if( pParse->nNode>=pParse->nAlloc ){
u32 nNew;
JsonNode *pNew;
if( pParse->oom ) return -1;
nNew = pParse->nAlloc*2 + 10;
if( nNew<=pParse->nNode ){
pParse->oom = 1;
return -1;
}
pNew = sqlite3_realloc(pParse->aNode, sizeof(JsonNode)*nNew);
if( pNew==0 ){
pParse->oom = 1;
return -1;
}
pParse->nAlloc = nNew;
pParse->aNode = pNew;
}
p = &pParse->aNode[pParse->nNode];
p->eType = eType;
p->n = n;
p->zContent = zContent;
return pParse->nNode++;
}
/*
** Parse a single JSON value which begins at pParse->zJson[i]. Return the
** index of the first character past the end of the value parsed.
**
** Return negative for a syntax error. Special cases: return -2 if the
** first non-whitespace character is '}' and return -3 if the first
** non-whitespace character is ']'.
*/
static int jsonParseValue(JsonParse *pParse, u32 i){
char c;
u32 j;
u32 iThis;
int x;
while( isspace(pParse->zJson[i]) ){ i++; }
if( (c = pParse->zJson[i])==0 ) return 0;
if( c=='{' ){
/* Parse object */
iThis = jsonParseAddNode(pParse, JSON_OBJECT, 0, 0);
if( iThis<0 ) return -1;
for(j=i+1;;j++){
while( isspace(pParse->zJson[j]) ){ j++; }
x = jsonParseValue(pParse, j);
if( x<0 ){
if( x==(-2) && pParse->nNode==iThis+1 ) return j+1;
return -1;
}
if( pParse->aNode[pParse->nNode-1].eType!=JSON_STRING ) return -1;
j = x;
while( isspace(pParse->zJson[j]) ){ j++; }
if( pParse->zJson[j]!=':' ) return -1;
j++;
x = jsonParseValue(pParse, j);
if( x<0 ) return -1;
j = x;
while( isspace(pParse->zJson[j]) ){ j++; }
c = pParse->zJson[j];
if( c==',' ) continue;
if( c!='}' ) return -1;
break;
}
pParse->aNode[iThis].n = pParse->nNode - iThis - 1;
return j+1;
}else if( c=='[' ){
/* Parse array */
iThis = jsonParseAddNode(pParse, JSON_ARRAY, 0, 0);
if( iThis<0 ) return -1;
for(j=i+1;;j++){
while( isspace(pParse->zJson[j]) ){ j++; }
x = jsonParseValue(pParse, j);
if( x<0 ){
if( x==(-3) && pParse->nNode==iThis+1 ) return j+1;
return -1;
}
j = x;
while( isspace(pParse->zJson[j]) ){ j++; }
c = pParse->zJson[j];
if( c==',' ) continue;
if( c!=']' ) return -1;
break;
}
pParse->aNode[iThis].n = pParse->nNode - iThis - 1;
return j+1;
}else if( c=='"' ){
/* Parse string */
j = i+1;
for(;;){
c = pParse->zJson[j];
if( c==0 ) return -1;
if( c=='\\' ){
c = pParse->zJson[++j];
if( c==0 ) return -1;
}else if( c=='"' ){
break;
}
j++;
}
jsonParseAddNode(pParse, JSON_STRING, j+1-i, &pParse->zJson[i]);
return j+1;
}else if( c=='n'
&& strncmp(pParse->zJson+i,"null",4)==0
&& !isalnum(pParse->zJson[i+5]) ){
jsonParseAddNode(pParse, JSON_NULL, 0, 0);
return i+4;
}else if( c=='t'
&& strncmp(pParse->zJson+i,"true",4)==0
&& !isalnum(pParse->zJson[i+5]) ){
jsonParseAddNode(pParse, JSON_TRUE, 0, 0);
return i+4;
}else if( c=='f'
&& strncmp(pParse->zJson+i,"false",5)==0
&& !isalnum(pParse->zJson[i+6]) ){
jsonParseAddNode(pParse, JSON_FALSE, 0, 0);
return i+5;
}else if( c=='-' || (c>='0' && c<='9') ){
/* Parse number */
u8 seenDP = 0;
u8 seenE = 0;
j = i+1;
for(;; j++){
c = pParse->zJson[j];
if( c>='0' && c<='9' ) continue;
if( c=='.' ){
if( pParse->zJson[j-1]=='-' ) return -1;
if( seenDP ) return -1;
seenDP = 1;
continue;
}
if( c=='e' || c=='E' ){
if( pParse->zJson[j-1]<'0' ) return -1;
if( seenE ) return -1;
seenDP = seenE = 1;
c = pParse->zJson[j+1];
if( c=='+' || c=='-' ) j++;
continue;
}
break;
}
if( pParse->zJson[j-1]<'0' ) return -1;
jsonParseAddNode(pParse, seenDP ? JSON_REAL : JSON_INT,
j - i, &pParse->zJson[i]);
return j;
}else if( c=='}' ){
return -2; /* End of {...} */
}else if( c==']' ){
return -3; /* End of [...] */
}else{
return -1; /* Syntax error */
}
}
/*
** Parse a complete JSON string. Return 0 on success or non-zero if there
** are any errors. If an error occurs, free all memory associated with
** pParse.
**
** pParse is uninitialized when this routine is called.
*/
static int jsonParse(JsonParse *pParse, const char *zJson){
int i;
if( zJson==0 ) return 1;
memset(pParse, 0, sizeof(*pParse));
pParse->zJson = zJson;
i = jsonParseValue(pParse, 0);
if( i>0 ){
while( isspace(zJson[i]) ) i++;
if( zJson[i] ) i = -1;
}
if( i<0 ){
sqlite3_free(pParse->aNode);
pParse->aNode = 0;
pParse->nNode = 0;
pParse->nAlloc = 0;
return 1;
}
return 0;
}
/*
** The json_debug(JSON) function returns a string which describes
** a parse of the JSON provided. Or it returns NULL if JSON is not
** well-formed.
*/
static void jsonDebugFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
Json s; /* Output string - not real JSON */
JsonParse x; /* The parse */
u32 i;
char zBuf[50];
static const char *azType[] = {
"NULL", "TRUE", "FALSE", "INT", "REAL", "STRING", "ARRAY", "OBJECT"
};
assert( argc==1 );
if( jsonParse(&x, (const char*)sqlite3_value_text(argv[0])) ) return;
jsonInit(&s, context);
for(i=0; i<x.nNode; i++){
sqlite3_snprintf(sizeof(zBuf), zBuf, "node %u:\n", i);
jsonAppend(&s, zBuf);
sqlite3_snprintf(sizeof(zBuf), zBuf, " type: %s\n",
azType[x.aNode[i].eType]);
jsonAppend(&s, zBuf);
if( x.aNode[i].eType>=JSON_INT ){
sqlite3_snprintf(sizeof(zBuf), zBuf, " n: %u\n", x.aNode[i].n);
jsonAppend(&s, zBuf);
}
if( x.aNode[i].zContent!=0 ){
sqlite3_snprintf(sizeof(zBuf), zBuf, " ofst: %u\n",
(u32)(x.aNode[i].zContent - x.zJson));
jsonAppend(&s, zBuf);
jsonAppendRaw(&s, " text: ", 8);
jsonAppendRaw(&s, x.aNode[i].zContent, x.aNode[i].n);
jsonAppendRaw(&s, "\n", 1);
}
}
sqlite3_free(x.aNode);
jsonResult(&s);
}
#ifdef _WIN32
__declspec(dllexport)
#endif
@@ -540,6 +805,7 @@ int sqlite3_json_init(
{ "json_array", -1, jsonArrayFunc },
{ "jsonb_array", -1, jsonbArrayFunc },
{ "json_object", -1, jsonObjectFunc },
{ "json_debug", 1, jsonDebugFunc },
};
SQLITE_EXTENSION_INIT2(pApi);
(void)pzErrMsg; /* Unused parameter */
manifest
+6 -6
View File
@@ -1,5 +1,5 @@
C Experimental\scode\s(untested)\sfor\sa\sJSONB\sdatatype.
D 2015-08-13T13:54:59.587
C Add\sa\sprototype\sJSON\sparser.
D 2015-08-15T21:25:37.000
F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
F Makefile.in 7669f34c487f5b328de6b508f374ee1e56558bb0
F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -192,7 +192,7 @@ F ext/misc/eval.c f971962e92ebb8b0a4e6b62949463ee454d88fa2
F ext/misc/fileio.c d4171c815d6543a9edef8308aab2951413cd8d0f
F ext/misc/fuzzer.c 4c84635c71c26cfa7c2e5848cf49fe2d2cfcd767
F ext/misc/ieee754.c b0362167289170627659e84173f5d2e8fee8566e
F ext/misc/json.c 748c5bffa8840f1b0bdc4b5ff672949c31c7f436
F ext/misc/json.c f4fa58cb8c6a7e13ae9a357e8c5783f43c60f595
F ext/misc/nextchar.c 35c8b8baacb96d92abbb34a83a997b797075b342
F ext/misc/percentile.c bcbee3c061b884eccb80e21651daaae8e1e43c63
F ext/misc/regexp.c af92cdaa5058fcec1451e49becc7ba44dba023dc
@@ -1374,7 +1374,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
F tool/warnings.sh 48bd54594752d5be3337f12c72f28d2080cb630b
F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
P 414a95f3b79359f167858b2325fd2be223569c66
R 45e5df2bce81d8e555551bffb25d0cb6
P e3596ac7b1dd5bde3f9cae5781a6806d8d9f7166
R 45c6bd1bef56b998d07e7b3125f794b3
U drh
Z 62911abad9701038f8848b5004ef4c38
Z e2e8ec51bb6080feb16e3eda35039c7d
manifest.uuid
+1 -1
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@@ -1 +1 @@
e3596ac7b1dd5bde3f9cae5781a6806d8d9f7166
789ba487000aa73621a41d115ad5de455ea8ea31