summaryrefslogtreecommitdiffstats
path: root/ext/misc/eval.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-05 17:28:19 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-05 17:28:19 +0000
commit18657a960e125336f704ea058e25c27bd3900dcb (patch)
tree17b438b680ed45a996d7b59951e6aa34023783f2 /ext/misc/eval.c
parentInitial commit. (diff)
downloadsqlite3-upstream.tar.xz
sqlite3-upstream.zip
Adding upstream version 3.40.1.upstream/3.40.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'ext/misc/eval.c')
-rw-r--r--ext/misc/eval.c125
1 files changed, 125 insertions, 0 deletions
diff --git a/ext/misc/eval.c b/ext/misc/eval.c
new file mode 100644
index 0000000..d3849d6
--- /dev/null
+++ b/ext/misc/eval.c
@@ -0,0 +1,125 @@
+/*
+** 2014-11-10
+**
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
+**
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This SQLite extension implements SQL function eval() which runs
+** SQL statements recursively.
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#include <string.h>
+
+/*
+** Structure used to accumulate the output
+*/
+struct EvalResult {
+ char *z; /* Accumulated output */
+ const char *zSep; /* Separator */
+ int szSep; /* Size of the separator string */
+ sqlite3_int64 nAlloc; /* Number of bytes allocated for z[] */
+ sqlite3_int64 nUsed; /* Number of bytes of z[] actually used */
+};
+
+/*
+** Callback from sqlite_exec() for the eval() function.
+*/
+static int callback(void *pCtx, int argc, char **argv, char **colnames){
+ struct EvalResult *p = (struct EvalResult*)pCtx;
+ int i;
+ if( argv==0 ) return 0;
+ for(i=0; i<argc; i++){
+ const char *z = argv[i] ? argv[i] : "";
+ size_t sz = strlen(z);
+ if( (sqlite3_int64)sz+p->nUsed+p->szSep+1 > p->nAlloc ){
+ char *zNew;
+ p->nAlloc = p->nAlloc*2 + sz + p->szSep + 1;
+ /* Using sqlite3_realloc64() would be better, but it is a recent
+ ** addition and will cause a segfault if loaded by an older version
+ ** of SQLite. */
+ zNew = p->nAlloc<=0x7fffffff ? sqlite3_realloc64(p->z, p->nAlloc) : 0;
+ if( zNew==0 ){
+ sqlite3_free(p->z);
+ memset(p, 0, sizeof(*p));
+ return 1;
+ }
+ p->z = zNew;
+ }
+ if( p->nUsed>0 ){
+ memcpy(&p->z[p->nUsed], p->zSep, p->szSep);
+ p->nUsed += p->szSep;
+ }
+ memcpy(&p->z[p->nUsed], z, sz);
+ p->nUsed += sz;
+ }
+ return 0;
+}
+
+/*
+** Implementation of the eval(X) and eval(X,Y) SQL functions.
+**
+** Evaluate the SQL text in X. Return the results, using string
+** Y as the separator. If Y is omitted, use a single space character.
+*/
+static void sqlEvalFunc(
+ sqlite3_context *context,
+ int argc,
+ sqlite3_value **argv
+){
+ const char *zSql;
+ sqlite3 *db;
+ char *zErr = 0;
+ int rc;
+ struct EvalResult x;
+
+ memset(&x, 0, sizeof(x));
+ x.zSep = " ";
+ zSql = (const char*)sqlite3_value_text(argv[0]);
+ if( zSql==0 ) return;
+ if( argc>1 ){
+ x.zSep = (const char*)sqlite3_value_text(argv[1]);
+ if( x.zSep==0 ) return;
+ }
+ x.szSep = (int)strlen(x.zSep);
+ db = sqlite3_context_db_handle(context);
+ rc = sqlite3_exec(db, zSql, callback, &x, &zErr);
+ if( rc!=SQLITE_OK ){
+ sqlite3_result_error(context, zErr, -1);
+ sqlite3_free(zErr);
+ }else if( x.zSep==0 ){
+ sqlite3_result_error_nomem(context);
+ sqlite3_free(x.z);
+ }else{
+ sqlite3_result_text(context, x.z, (int)x.nUsed, sqlite3_free);
+ }
+}
+
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_eval_init(
+ sqlite3 *db,
+ char **pzErrMsg,
+ const sqlite3_api_routines *pApi
+){
+ int rc = SQLITE_OK;
+ SQLITE_EXTENSION_INIT2(pApi);
+ (void)pzErrMsg; /* Unused parameter */
+ rc = sqlite3_create_function(db, "eval", 1,
+ SQLITE_UTF8|SQLITE_DIRECTONLY, 0,
+ sqlEvalFunc, 0, 0);
+ if( rc==SQLITE_OK ){
+ rc = sqlite3_create_function(db, "eval", 2,
+ SQLITE_UTF8|SQLITE_DIRECTONLY, 0,
+ sqlEvalFunc, 0, 0);
+ }
+ return rc;
+}