give the "get" method the asynchronous synchronous treatment

generic/zookeepertcl.c

@@ -465,7 +465,10 @@ zootcl_sync_stat_completion_callback (int rc, const struct Stat *stat, const voi
  zootcl_syncCallbackContext *zsc = (zootcl_syncCallbackContext *)context;
  zootcl_callbackEvent *evPtr;
  zsc->rc = rc;
- if (stat != NULL) {
+ if (stat == NULL) {
+ zsc->haveStat = 0;
+ } else {
+ zsc->haveStat = 1;
  zsc->stat = *stat;
  }
  zsc->syncDone = 1;
@@ -477,6 +480,46 @@ printf("zootcl_sync_stat_completion_callback: done\n");
  Tcl_ThreadAlert (zsc->zo->threadId);
 }
 
+/*
+ *--------------------------------------------------------------
+ *
+ * zootcl_sync_data_completion_callback -- data completion callback function
+ *
+ *--------------------------------------------------------------
+ */
+void
+zootcl_sync_data_completion_callback (int rc, const char *value, int valueLen, const struct Stat *stat, const void *context)
+{
+ zootcl_callbackEvent *evPtr;
+ zootcl_syncCallbackContext *zsc = (zootcl_syncCallbackContext *)context;
+
+ evPtr = ckalloc (sizeof (zootcl_callbackEvent));
+ evPtr->event.proc = zootcl_EventProc;
+ evPtr->callbackType = NULL_CALLBACK;
+
+ zsc->rc = rc;
+ zsc->syncDone = 1;
+
+ // if value is NULL then there is no value associated with this znode
+ // we set to NULL and the other end (the event handler) will discriminate
+ if (value == NULL) {
+ zsc->dataObj = NULL;
+ } else {
+ zsc->dataObj = Tcl_NewStringObj (value, valueLen);
+ }
+
+ // structure copy status structure only if it exists
+ if (stat == NULL) {
+ zsc->haveStat = 0;
+ } else {
+ zsc->haveStat = 1;
+ zsc->stat = *stat;
+ }
+
+ Tcl_ThreadQueueEvent (zsc->zo->threadId, (Tcl_Event *)evPtr, TCL_QUEUE_TAIL);
+ Tcl_ThreadAlert (zsc->zo->threadId);
+}
+
 /*
  *--------------------------------------------------------------
  *
@@ -1217,11 +1260,7 @@ zootcl_get_subcommand(Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[], ZOOAP
  };
 
  const char *path;
- char buffer[1024*1024];
- int bufferLen = sizeof(buffer);
  watcher_fn wfn = NULL;
- struct Stat *stat = NULL;
- struct Stat statBuf;
 
  assert (zo->zookeeper_object_magic == ZOOKEEPER_OBJECT_MAGIC);
 
@@ -1276,7 +1315,6 @@ zootcl_get_subcommand(Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[], ZOOAP
  return TCL_ERROR;
  }
  statArray = Tcl_GetString (objv[++i]);
- stat = &statBuf;
  break;
  }
 
@@ -1297,7 +1335,6 @@ zootcl_get_subcommand(Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[], ZOOAP
  return TCL_ERROR;
  }
  versionVarObj = objv[++i];
- stat = &statBuf;
  break;
  }
  }
@@ -1328,8 +1365,16 @@ zootcl_get_subcommand(Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[], ZOOAP
 
  // if asyncCallbackObj is null, do the synchronous version
  if (asyncCallbackObj == NULL) {
- status = zoo_wget (zh, path, wfn, (void *)watcherCallbackObj, buffer, &bufferLen, stat);
- if ((status == ZNONODE) && (dataVarObj != NULL)) {
+ // synchronous get
+ zootcl_syncCallbackContext *zsc = (zootcl_syncCallbackContext *)ckalloc (sizeof (zootcl_syncCallbackContext));
+ zsc->zo = zo;
+ zsc->syncDone = 0;
+ status = zoo_awget (zh, path, wfn, (void *)watcherCallbackObj, zootcl_sync_data_completion_callback, zsc);
+ if (zootcl_wait (zo, zsc) == TCL_ERROR) {
+ return TCL_ERROR;
+ }
+ int rc = zsc->rc;
+ if ((rc == ZNONODE) && (dataVarObj != NULL)) {
  // node doesn't exist and they specified -data,
  // unset data var and version var if defined and
  // return 0 indicating no node
@@ -1341,30 +1386,31 @@ zootcl_get_subcommand(Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[], ZOOAP
  return TCL_OK;
  }
 
- if (status != ZOK) {
+ if (rc != ZOK) {
  return zootcl_set_tcl_return_code (interp, status);
  }
 
- if (bufferLen != -1) {
- if (dataVarObj == NULL) {
- Tcl_SetObjResult (interp, Tcl_NewStringObj (buffer, bufferLen));
- } else {
- if (Tcl_SetVar2Ex (interp, Tcl_GetString (dataVarObj), NULL, Tcl_NewStringObj (buffer, bufferLen), TCL_LEAVE_ERR_MSG) == NULL) {
- return TCL_ERROR;
- }
- Tcl_SetObjResult (interp, Tcl_NewBooleanObj (1));
+ if (dataVarObj == NULL) {
+ if (zsc->dataObj != NULL) {
+ Tcl_SetObjResult (interp, zsc->dataObj);
+ }
+ } else {
+ if (Tcl_SetVar2Ex (interp, Tcl_GetString (dataVarObj), NULL, zsc->dataObj, TCL_LEAVE_ERR_MSG) == NULL) {
+ return TCL_ERROR;
  }
+ Tcl_SetObjResult (interp, Tcl_NewBooleanObj (1));
  }
 
- if (statArray != NULL && zootcl_stat_to_array (interp, statArray, stat) == TCL_ERROR) {
+ if (zsc->haveStat && zootcl_stat_to_array (interp, statArray, &zsc->stat) == TCL_ERROR) {
  return TCL_ERROR;
  }
 
  if (versionVarObj != NULL) {
- if (Tcl_SetVar2Ex (interp, Tcl_GetString (versionVarObj), NULL, Tcl_NewIntObj (stat->version), TCL_LEAVE_ERR_MSG) == NULL) {
+ if (Tcl_SetVar2Ex (interp, Tcl_GetString (versionVarObj), NULL, Tcl_NewIntObj (zsc->stat.version), TCL_LEAVE_ERR_MSG) == NULL) {
  return TCL_ERROR;
  }
  }
+ ckfree (zsc);
  } else {
  // do the asynchronous version
  zootcl_callbackContext *ztc = (zootcl_callbackContext *)ckalloc (sizeof (zootcl_callbackContext));

generic/zookeepertcl.h

@@ -46,8 +46,10 @@ typedef struct zootcl_syncCallbackContext
 {
  zootcl_objectClientData *zo;
  int rc;
+ int haveStat;
  struct Stat stat;
  int syncDone;
+ Tcl_Obj *dataObj;
 } zootcl_syncCallbackContext;
 
 // this is the data structure that zookeepertcl queues to tcl