[ADDED] KeyValue: Support for Mirror and Sources

Also updated state for proper Put() and Get() semantics with mirrors and across domains, e.g. leafnodes. In practice when a mirror is across a domain, should be named the same as origin. That allows an app to run anywhere without anything special in terms of domains when binding to the KV itself. (Removed dead-code following previous PR #607) Signed-off-by: Ivan Kozlovic <[email protected]>
nats-io · Oct 27, 2022 · 2c87273 · 2c87273
1 parent 3a1250f
commit 2c87273
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Showing 7 changed files with 544 additions and 60 deletions.
diff --git a/src/js.h b/src/js.h
@@ -103,6 +103,9 @@ extern const int64_t    jsDefaultRequestWait;
 #define jsAckInProgress     "+WPI"
 #define jsAckTerm           "+TERM"
 
+// jsExtDomainT is used to create a StreamSource External APIPrefix
+#define jsExtDomainT "$JS.%s.API"
+
 // jsApiAccountInfo is for obtaining general information about JetStream.
 #define jsApiAccountInfo "%.*s.INFO"
 

diff --git a/src/jsm.c b/src/jsm.c
@@ -264,8 +264,11 @@ _marshalExternalStream(jsExternalStream *external, const char *fieldName, natsBu
     IFOK(s, natsBuf_Append(buf, fieldName, -1));
     IFOK(s, natsBuf_Append(buf, "\":{\"api\":\"", -1));
     IFOK(s, natsBuf_Append(buf, external->APIPrefix, -1));
-    IFOK(s, natsBuf_Append(buf, "\",\"deliver\":\"", -1));
-    IFOK(s, natsBuf_Append(buf, external->DeliverPrefix, -1));
+    if ((s == NATS_OK) && !nats_IsStringEmpty(external->DeliverPrefix))
+    {
+        IFOK(s, natsBuf_Append(buf, "\",\"deliver\":\"", -1));
+        IFOK(s, natsBuf_Append(buf, external->DeliverPrefix, -1));
+    }
     IFOK(s, natsBuf_Append(buf, "\"}", -1));
 
     return NATS_UPDATE_ERR_STACK(s);
@@ -1061,6 +1064,95 @@ jsStreamConfig_Init(jsStreamConfig *cfg)
     return NATS_OK;
 }
 
+static void
+_restoreMirrorAndSourcesExternal(jsStreamConfig *cfg)
+{
+    int i;
+
+    // We are guaranteed that if a source's Domain is set, there was originally
+    // no External value. So free any External value and reset to NULL to
+    // restore the original setting.
+    if ((cfg->Mirror != NULL) && !nats_IsStringEmpty(cfg->Mirror->Domain))
+    {
+        _destroyExternalStream(cfg->Mirror->External);
+        cfg->Mirror->External = NULL;
+    }
+    for (i=0; i<cfg->SourcesLen; i++)
+    {
+        jsStreamSource *src = cfg->Sources[i];
+        if ((src != NULL) && !nats_IsStringEmpty(src->Domain))
+        {
+            _destroyExternalStream(src->External);
+            src->External = NULL;
+        }
+    }
+}
+
+static natsStatus
+_convertDomain(jsStreamSource *src)
+{
+    jsExternalStream *e = NULL;
+
+    e = (jsExternalStream*) NATS_CALLOC(1, sizeof(jsExternalStream));
+    if (e == NULL)
+        return nats_setDefaultError(NATS_NO_MEMORY);
+
+    if (nats_asprintf((char**) &(e->APIPrefix), jsExtDomainT, src->Domain) < 0)
+    {
+        NATS_FREE(e);
+        return nats_setDefaultError(NATS_NO_MEMORY);
+    }
+    src->External = e;
+    return NATS_OK;
+}
+
+static natsStatus
+_convertMirrorAndSourcesDomain(bool *converted, jsStreamConfig *cfg)
+{
+    natsStatus  s   = NATS_OK;
+    bool        cm  = false;
+    bool        cs  = false;
+    int         i;
+
+    *converted = false;
+
+    if ((cfg->Mirror != NULL) && !nats_IsStringEmpty(cfg->Mirror->Domain))
+    {
+        if (cfg->Mirror->External != NULL)
+            return nats_setError(NATS_INVALID_ARG, "%s", "mirror's domain and external are both set");
+        cm = true;
+    }
+    for (i=0; i<cfg->SourcesLen; i++)
+    {
+        jsStreamSource *src = cfg->Sources[i];
+        if ((src != NULL) && !nats_IsStringEmpty(src->Domain))
+        {
+            if (src->External != NULL)
+                return nats_setError(NATS_INVALID_ARG, "%s", "source's domain and external are both set");
+            cs = true;
+        }
+    }
+    if (!cm && !cs)
+        return NATS_OK;
+
+    if (cm)
+        s = _convertDomain(cfg->Mirror);
+    if ((s == NATS_OK) && cs)
+    {
+        for (i=0; (s == NATS_OK) && (i<cfg->SourcesLen); i++)
+        {
+            jsStreamSource *src = cfg->Sources[i];
+            if ((src != NULL) && !nats_IsStringEmpty(src->Domain))
+                s = _convertDomain(src);
+        }
+    }
+    if (s == NATS_OK)
+        *converted = true;
+    else
+        _restoreMirrorAndSourcesExternal(cfg);
+    return NATS_UPDATE_ERR_STACK(s);
+}
+
 static natsStatus
 _addOrUpdate(jsStreamInfo **new_si, jsStreamAction action, jsCtx *js, jsStreamConfig *cfg, jsOptions *opts, jsErrCode *errCode)
 {
@@ -1071,6 +1163,7 @@ _addOrUpdate(jsStreamInfo **new_si, jsStreamAction action, jsCtx *js, jsStreamCo
     natsConnection      *nc     = NULL;
     const char          *apiT   = NULL;
     bool                freePfx = false;
+    bool                msc     = false;
     jsOptions           o;
 
     if (errCode != NULL)
@@ -1101,6 +1194,8 @@ _addOrUpdate(jsStreamInfo **new_si, jsStreamAction action, jsCtx *js, jsStreamCo
         if (freePfx)
             NATS_FREE((char*) o.Prefix);
     }
+    if ((s == NATS_OK) && (action == jsStreamActionCreate))
+        s = _convertMirrorAndSourcesDomain(&msc, cfg);
 
     // Marshal the stream create/update request
     IFOK(s, js_marshalStreamConfig(&buf, cfg));
@@ -1111,6 +1206,12 @@ _addOrUpdate(jsStreamInfo **new_si, jsStreamAction action, jsCtx *js, jsStreamCo
     // If we got a response, check for error or return the stream info result.
     IFOK(s, _unmarshalStreamCreateResp(new_si, NULL, resp, errCode));
 
+    // If mirror and/or sources were converted for the domain, then we need
+    // to restore the original values (which will free the memory that was
+    // allocated for the conversion).
+    if (msc)
+        _restoreMirrorAndSourcesExternal(cfg);
+
     natsBuf_Destroy(buf);
     natsMsg_Destroy(resp);
     NATS_FREE(subj);