own the state

Signed-off-by: Tobias Gurtzick <[email protected]>

Author: wzrdtales

lib/state.js

@@ -1,33 +1,68 @@
 const MSTATE = '__dbmigrate_state__';
 const SSTATE = '__dbmigrate_schema__';
+const RUNON =
+        'run_on';
+
 const log = require('db-migrate-shared').log;
 const fs = require('fs').promises;
 const path = require('path');
+const crypto = require('crypto');
+
+const ID = crypto.randomBytes(32).toString('base64');
+let owner = false;
 
 module.exports = {
+  /**
+   * Lock state will add the basic state controller an ID
+   * and a process controlled date.
+   * It is important that all systems are in sync. We will use the
+   * database clock instead if possible.
+   */
   lockState: async function (driver, state, internals) {
     if (!state) {
+      owner = true;
       return driver._insertKV(
         internals.migrationState,
         MSTATE,
         JSON.stringify({
           s: {
             step: 0,
             fin: 0,
+            ID,
             date: new Date()
           }
         })
       );
     } else {
+      let runOn = state.run_on;
       state = state.value;
       state = JSON.parse(state);
-      state.s.date = new Date();
-      return driver._updateKV(
+
+      if (!state.s.ID || state.s.ID !== ID) {
+        owner = true;
+        state.s.ID = ID;
+      }
+
+      const d = new Date();
+
+      state.s.date = d;
+      await driver._updateKVC(
         internals.migrationState,
         MSTATE,
-
-        JSON.stringify(state)
+        JSON.stringify(state),
+        RUNON,
+        runOn
       );
+
+      state = await driver._getKV(internals.migrationState, MSTATE);
+
+      runOn = state.run_on;
+      state = state.value;
+      state = JSON.parse(state);
+
+      if (state.s.ID !== ID) {
+        owner = false;
+      }
     }
   },
 
@@ -165,6 +200,9 @@ module.exports = {
     state.s.date = new Date();
     state.s.fin = 1;
 
+    // unlock from current process
+    state.s.ID = 0;
+
     return driver._updateKV(
       internals.migrationState,
       MSTATE,