Improved (sync/backup) scripts + misc updates

-Added locks to all sync processes (blocks, markets, peers, masternodes) as well as "create backup", "restore backup" and "delete database" functions. This helps prevent problems with syncing data while a backup is in progress for example -The code to initialize certain database collections on startup was moved into database.js and is now called from restore_backup.js and delete_database.js. This effectively allows the database to be deleted or restored to a completely different backup while the explorer is still running -Lock functions (create_lock, remove_lock, is_locked) were moved into explorer.js for better reusability and rewriten to be synchronous -is_locked function now accepts an array of lock files to be able to check for multiple locks in a single call -remove_sync_message() function was moved into database.js so that restore_backup.js and delete_database.js can also check for and remove the sync msg if it exists -Useful Scripts section updated in the README to make it clear that the explorer no longer needs to be stopped for these scripts to be run -Most if not all log messages now start with a capitlal letter
2022-04-30 20:53:10 -06:00
parent 8e32e294b7
commit d7c18a48f5
9 changed files with 1085 additions and 854 deletions
@@ -1315,5 +1315,93 @@ module.exports = {
    }, function() {
      return cb(arr_vin, tx_type);
    });
+  },
+
+  create_lock: function(lock) {
+    const fs = require('fs');
+    var fname = './tmp/' + lock + '.pid';
+
+    try {
+      fs.appendFileSync(fname, process.pid.toString());
+      return true;
+    } catch(err) {
+      console.log("Error: Unable to remove lock: %s", fname);
+      return false;
+    }
+  },
+
+  remove_lock: function(lock) {
+    const fs = require('fs');
+    var fname = './tmp/' + lock + '.pid';
+
+    try {
+      fs.unlinkSync(fname);
+      return true;
+    } catch(err) {
+      console.log("Error: Unable to remove lock: %s", fname);
+      return false;
+    }
+  },
+
+  is_locked: function(lock_array) {
+    const fs = require('fs');
+    const path = require('path');
+    var retVal = false;
+
+    // loop through all lock files that need to be checked
+    for (var i = 0; i < lock_array.length; i++) {
+      var pidFile = path.join(path.dirname(__dirname), 'tmp', `${lock_array[i]}.pid`);
+
+      // check if the script is already running (tmp/file.pid file already exists)
+      if (fs.existsSync(pidFile)) {
+        const { execSync } = require('child_process');
+        var deactivateLock = false;
+
+        // the pid file exists
+        // determine the operating system
+        switch (process.platform) {
+          case 'win32':
+            // windows
+            // run a cmd that will determine if the lock should still be active
+            var cmdResult = execSync(`tasklist /FI "PID eq ${fs.readFileSync(pidFile).toString()}"`);
+
+            // check if the process that created the lock is actually still running (crude check by testing for # of carriage returns or node.exe process running, but should work universally across different systems and languages)
+            if (cmdResult.toString().split('\n').length < 4 || cmdResult.toString().toLowerCase().indexOf('\nnode.exe') == -1) {
+              // lock should be deactivated
+              deactivateLock = true;
+            }
+
+            break;
+          default:
+            // linux or other
+            // run a cmd that will determine if the lock should still be active
+
+            try {
+              var cmdResult = execSync('ps -p `cat ' + pidFile + '` > /dev/null');
+            } catch (err) {
+              // if an error occurs, the process is NOT running and therefore the lock should be deactivated
+              deactivateLock = true;
+            }
+        }
+
+        // check if the lock should be deactivated
+        if (deactivateLock) {
+          // script is not actually running so the lock file can be deleted
+          try {
+            fs.rmSync(pidFile);
+          } catch(err) {
+            console.log(`Failed to delete lock file ${pidFile}: ${err}`);
+          }
+        } else {
+          // script is running
+          console.log(`${lock_array[i]} script is running..`);
+          retVal = true;
+
+          break;
+        }
+      }
+    }
+
+    return retVal;
  }
 };