/*
* Drop a record from a given collection.
*/
UNQLITE_PRIVATE int unqliteCollectionDropRecord(
unqlite_col *pCol, /* Target collection */
jx9_int64 nId, /* Unique ID of the record to be droped */
int wr_header, /* True to alter collection header */
int log_err /* True to log error */
)
{
SyBlob *pWorker = &pCol->sWorker;
int rc;
/* Reset the working buffer */
SyBlobReset(pWorker);
/* Prepare the unique ID for this record */
SyBlobFormat(pWorker,"%z_%qd",&pCol->sName,nId);
/* Reset the cursor */
unqlite_kv_cursor_reset(pCol->pCursor);
/* Seek the cursor to the desired location */
rc = unqlite_kv_cursor_seek(pCol->pCursor,
SyBlobData(pWorker),SyBlobLength(pWorker),
UNQLITE_CURSOR_MATCH_EXACT
);
if( rc != UNQLITE_OK ){
return rc;
}
/* Remove the record from the storage engine */
rc = unqlite_kv_cursor_delete_entry(pCol->pCursor);
/* Finally, Remove the record from the cache */
unqliteCollectionCacheRemoveRecord(pCol,nId);
if( rc == UNQLITE_OK ){
pCol->nTotRec--;
if( wr_header ){
/* Relect in the collection header */
rc = CollectionSetHeader(0,pCol,-1,pCol->nTotRec,0);
}
}else if( rc == UNQLITE_NOTIMPLEMENTED ){
if( log_err ){
unqliteGenErrorFormat(pCol->pVm->pDb,
"Cannot delete record from collection '%z' due to a read-only Key/Value storage engine",
&pCol->sName
);
}
}
return rc;
}
/*
* array db_fetch_all(string $col_name,[callback filter_callback])
* array db_get_all(string $col_name,[callback filter_callback])
* Retrieve all records of a given collection and apply the given
* callback if available to filter records.
* Parameter
* col_name: Collection name
* Return
* Contents of the collection (JSON array) on success. NULL on failure.
*/
static int unqliteBuiltin_db_fetch_all(jx9_context *pCtx,int argc,jx9_value **argv)
{
unqlite_col *pCol;
const char *zName;
unqlite_vm *pVm;
SyString sName;
int nByte;
int rc;
/* Extract collection name */
if( argc < 1 ){
/* Missing arguments */
jx9_context_throw_error(pCtx,JX9_CTX_ERR,"Missing collection name");
/* Return NULL */
jx9_result_null(pCtx);
return JX9_OK;
}
zName = jx9_value_to_string(argv[0],&nByte);
if( nByte < 1){
jx9_context_throw_error(pCtx,JX9_CTX_ERR,"Invalid collection name");
/* Return NULL */
jx9_result_null(pCtx);
return JX9_OK;
}
SyStringInitFromBuf(&sName,zName,nByte);
pVm = (unqlite_vm *)jx9_context_user_data(pCtx);
/* Fetch the collection */
pCol = unqliteCollectionFetch(pVm,&sName,UNQLITE_VM_AUTO_LOAD);
if( pCol ){
jx9_value *pValue,*pArray,*pCallback = 0;
jx9_value sResult; /* Callback result */
/* Allocate an empty scalar value and an empty JSON array */
pArray = jx9_context_new_array(pCtx);
pValue = jx9_context_new_scalar(pCtx);
jx9MemObjInit(pCtx->pVm,&sResult);
if( pValue == 0 || pArray == 0 ){
jx9_context_throw_error(pCtx,JX9_CTX_ERR,"Jx9 is running out of memory");
jx9_result_null(pCtx);
return JX9_OK;
}
if( argc > 1 && jx9_value_is_callable(argv[1]) ){
pCallback = argv[1];
}
unqliteCollectionResetRecordCursor(pCol);
/* Fetch collection records one after one */
while( UNQLITE_OK == unqliteCollectionFetchNextRecord(pCol,pValue) ){
if( pCallback ){
jx9_value *apArg[2];
/* Invoke the filter callback */
apArg[0] = pValue;
rc = jx9VmCallUserFunction(pCtx->pVm,pCallback,1,apArg,&sResult);
if( rc == JX9_OK ){
int iResult; /* Callback result */
/* Extract callback result */
iResult = jx9_value_to_bool(&sResult);
if( !iResult ){
/* Discard the result */
unqliteCollectionCacheRemoveRecord(pCol,unqliteCollectionCurrentRecordId(pCol) - 1);
continue;
}
}
}
/* Put the value in the JSON array */
jx9_array_add_elem(pArray,0,pValue);
/* Release the value */
jx9_value_null(pValue);
}
jx9MemObjRelease(&sResult);
/* Finally, return our array */
jx9_result_value(pCtx,pArray);
/* pValue will be automatically released as soon we return from
* this foreign function.
*/
}else{
/* No such collection, return null */
jx9_result_null(pCtx);
}
return JX9_OK;
}
