From a3ab42c157e545bd9ad0a46bcfdd33d41e81c441 Mon Sep 17 00:00:00 2001
From: Kevin Jahns <kevin.jahns@rwth-aachen.de>
Date: Tue, 30 Jan 2018 20:11:59 -0800
Subject: [PATCH] implemnt mutual exclude pattern directly in Persistence.js

---
 package-lock.json  | 912 +++++++++++++++++++++++++++++++++++++++++++++
 src/Persistence.js |  29 +-
 2 files changed, 928 insertions(+), 13 deletions(-)

diff --git a/package-lock.json b/package-lock.json
index 44a3e776..0fa92fc0 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1039,6 +1039,7 @@
       "requires": {
         "anymatch": "1.3.0",
         "async-each": "1.0.1",
+        "fsevents": "1.1.3",
         "glob-parent": "2.0.0",
         "inherits": "2.0.3",
         "is-binary-path": "1.0.1",
@@ -1990,6 +1991,910 @@
       "integrity": "sha1-FQStJSMVjKpA20onh8sBQRmU6k8=",
       "dev": true
     },
+    "fsevents": {
+      "version": "1.1.3",
+      "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-1.1.3.tgz",
+      "integrity": "sha512-WIr7iDkdmdbxu/Gh6eKEZJL6KPE74/5MEsf2whTOFNxbIoIixogroLdKYqB6FDav4Wavh/lZdzzd3b2KxIXC5Q==",
+      "dev": true,
+      "optional": true,
+      "requires": {
+        "nan": "2.8.0",
+        "node-pre-gyp": "0.6.39"
+      },
+      "dependencies": {
+        "abbrev": {
+          "version": "1.1.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "ajv": {
+          "version": "4.11.8",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "co": "4.6.0",
+            "json-stable-stringify": "1.0.1"
+          }
+        },
+        "ansi-regex": {
+          "version": "2.1.1",
+          "bundled": true,
+          "dev": true
+        },
+        "aproba": {
+          "version": "1.1.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "are-we-there-yet": {
+          "version": "1.1.4",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "delegates": "1.0.0",
+            "readable-stream": "2.2.9"
+          }
+        },
+        "asn1": {
+          "version": "0.2.3",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "assert-plus": {
+          "version": "0.2.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "asynckit": {
+          "version": "0.4.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "aws-sign2": {
+          "version": "0.6.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "aws4": {
+          "version": "1.6.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "balanced-match": {
+          "version": "0.4.2",
+          "bundled": true,
+          "dev": true
+        },
+        "bcrypt-pbkdf": {
+          "version": "1.0.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "tweetnacl": "0.14.5"
+          }
+        },
+        "block-stream": {
+          "version": "0.0.9",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "inherits": "2.0.3"
+          }
+        },
+        "boom": {
+          "version": "2.10.1",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "hoek": "2.16.3"
+          }
+        },
+        "brace-expansion": {
+          "version": "1.1.7",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "balanced-match": "0.4.2",
+            "concat-map": "0.0.1"
+          }
+        },
+        "buffer-shims": {
+          "version": "1.0.0",
+          "bundled": true,
+          "dev": true
+        },
+        "caseless": {
+          "version": "0.12.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "co": {
+          "version": "4.6.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "code-point-at": {
+          "version": "1.1.0",
+          "bundled": true,
+          "dev": true
+        },
+        "combined-stream": {
+          "version": "1.0.5",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "delayed-stream": "1.0.0"
+          }
+        },
+        "concat-map": {
+          "version": "0.0.1",
+          "bundled": true,
+          "dev": true
+        },
+        "console-control-strings": {
+          "version": "1.1.0",
+          "bundled": true,
+          "dev": true
+        },
+        "core-util-is": {
+          "version": "1.0.2",
+          "bundled": true,
+          "dev": true
+        },
+        "cryptiles": {
+          "version": "2.0.5",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "boom": "2.10.1"
+          }
+        },
+        "dashdash": {
+          "version": "1.14.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "assert-plus": "1.0.0"
+          },
+          "dependencies": {
+            "assert-plus": {
+              "version": "1.0.0",
+              "bundled": true,
+              "dev": true,
+              "optional": true
+            }
+          }
+        },
+        "debug": {
+          "version": "2.6.8",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "ms": "2.0.0"
+          }
+        },
+        "deep-extend": {
+          "version": "0.4.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "delayed-stream": {
+          "version": "1.0.0",
+          "bundled": true,
+          "dev": true
+        },
+        "delegates": {
+          "version": "1.0.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "detect-libc": {
+          "version": "1.0.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "ecc-jsbn": {
+          "version": "0.1.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "jsbn": "0.1.1"
+          }
+        },
+        "extend": {
+          "version": "3.0.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "extsprintf": {
+          "version": "1.0.2",
+          "bundled": true,
+          "dev": true
+        },
+        "forever-agent": {
+          "version": "0.6.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "form-data": {
+          "version": "2.1.4",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "asynckit": "0.4.0",
+            "combined-stream": "1.0.5",
+            "mime-types": "2.1.15"
+          }
+        },
+        "fs.realpath": {
+          "version": "1.0.0",
+          "bundled": true,
+          "dev": true
+        },
+        "fstream": {
+          "version": "1.0.11",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "graceful-fs": "4.1.11",
+            "inherits": "2.0.3",
+            "mkdirp": "0.5.1",
+            "rimraf": "2.6.1"
+          }
+        },
+        "fstream-ignore": {
+          "version": "1.0.5",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "fstream": "1.0.11",
+            "inherits": "2.0.3",
+            "minimatch": "3.0.4"
+          }
+        },
+        "gauge": {
+          "version": "2.7.4",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "aproba": "1.1.1",
+            "console-control-strings": "1.1.0",
+            "has-unicode": "2.0.1",
+            "object-assign": "4.1.1",
+            "signal-exit": "3.0.2",
+            "string-width": "1.0.2",
+            "strip-ansi": "3.0.1",
+            "wide-align": "1.1.2"
+          }
+        },
+        "getpass": {
+          "version": "0.1.7",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "assert-plus": "1.0.0"
+          },
+          "dependencies": {
+            "assert-plus": {
+              "version": "1.0.0",
+              "bundled": true,
+              "dev": true,
+              "optional": true
+            }
+          }
+        },
+        "glob": {
+          "version": "7.1.2",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "fs.realpath": "1.0.0",
+            "inflight": "1.0.6",
+            "inherits": "2.0.3",
+            "minimatch": "3.0.4",
+            "once": "1.4.0",
+            "path-is-absolute": "1.0.1"
+          }
+        },
+        "graceful-fs": {
+          "version": "4.1.11",
+          "bundled": true,
+          "dev": true
+        },
+        "har-schema": {
+          "version": "1.0.5",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "har-validator": {
+          "version": "4.2.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "ajv": "4.11.8",
+            "har-schema": "1.0.5"
+          }
+        },
+        "has-unicode": {
+          "version": "2.0.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "hawk": {
+          "version": "3.1.3",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "boom": "2.10.1",
+            "cryptiles": "2.0.5",
+            "hoek": "2.16.3",
+            "sntp": "1.0.9"
+          }
+        },
+        "hoek": {
+          "version": "2.16.3",
+          "bundled": true,
+          "dev": true
+        },
+        "http-signature": {
+          "version": "1.1.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "assert-plus": "0.2.0",
+            "jsprim": "1.4.0",
+            "sshpk": "1.13.0"
+          }
+        },
+        "inflight": {
+          "version": "1.0.6",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "once": "1.4.0",
+            "wrappy": "1.0.2"
+          }
+        },
+        "inherits": {
+          "version": "2.0.3",
+          "bundled": true,
+          "dev": true
+        },
+        "ini": {
+          "version": "1.3.4",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "is-fullwidth-code-point": {
+          "version": "1.0.0",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "number-is-nan": "1.0.1"
+          }
+        },
+        "is-typedarray": {
+          "version": "1.0.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "isarray": {
+          "version": "1.0.0",
+          "bundled": true,
+          "dev": true
+        },
+        "isstream": {
+          "version": "0.1.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "jodid25519": {
+          "version": "1.0.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "jsbn": "0.1.1"
+          }
+        },
+        "jsbn": {
+          "version": "0.1.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "json-schema": {
+          "version": "0.2.3",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "json-stable-stringify": {
+          "version": "1.0.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "jsonify": "0.0.0"
+          }
+        },
+        "json-stringify-safe": {
+          "version": "5.0.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "jsonify": {
+          "version": "0.0.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "jsprim": {
+          "version": "1.4.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "assert-plus": "1.0.0",
+            "extsprintf": "1.0.2",
+            "json-schema": "0.2.3",
+            "verror": "1.3.6"
+          },
+          "dependencies": {
+            "assert-plus": {
+              "version": "1.0.0",
+              "bundled": true,
+              "dev": true,
+              "optional": true
+            }
+          }
+        },
+        "mime-db": {
+          "version": "1.27.0",
+          "bundled": true,
+          "dev": true
+        },
+        "mime-types": {
+          "version": "2.1.15",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "mime-db": "1.27.0"
+          }
+        },
+        "minimatch": {
+          "version": "3.0.4",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "brace-expansion": "1.1.7"
+          }
+        },
+        "minimist": {
+          "version": "0.0.8",
+          "bundled": true,
+          "dev": true
+        },
+        "mkdirp": {
+          "version": "0.5.1",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "minimist": "0.0.8"
+          }
+        },
+        "ms": {
+          "version": "2.0.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "node-pre-gyp": {
+          "version": "0.6.39",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "detect-libc": "1.0.2",
+            "hawk": "3.1.3",
+            "mkdirp": "0.5.1",
+            "nopt": "4.0.1",
+            "npmlog": "4.1.0",
+            "rc": "1.2.1",
+            "request": "2.81.0",
+            "rimraf": "2.6.1",
+            "semver": "5.3.0",
+            "tar": "2.2.1",
+            "tar-pack": "3.4.0"
+          }
+        },
+        "nopt": {
+          "version": "4.0.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "abbrev": "1.1.0",
+            "osenv": "0.1.4"
+          }
+        },
+        "npmlog": {
+          "version": "4.1.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "are-we-there-yet": "1.1.4",
+            "console-control-strings": "1.1.0",
+            "gauge": "2.7.4",
+            "set-blocking": "2.0.0"
+          }
+        },
+        "number-is-nan": {
+          "version": "1.0.1",
+          "bundled": true,
+          "dev": true
+        },
+        "oauth-sign": {
+          "version": "0.8.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "object-assign": {
+          "version": "4.1.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "once": {
+          "version": "1.4.0",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "wrappy": "1.0.2"
+          }
+        },
+        "os-homedir": {
+          "version": "1.0.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "os-tmpdir": {
+          "version": "1.0.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "osenv": {
+          "version": "0.1.4",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "os-homedir": "1.0.2",
+            "os-tmpdir": "1.0.2"
+          }
+        },
+        "path-is-absolute": {
+          "version": "1.0.1",
+          "bundled": true,
+          "dev": true
+        },
+        "performance-now": {
+          "version": "0.2.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "process-nextick-args": {
+          "version": "1.0.7",
+          "bundled": true,
+          "dev": true
+        },
+        "punycode": {
+          "version": "1.4.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "qs": {
+          "version": "6.4.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "rc": {
+          "version": "1.2.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "deep-extend": "0.4.2",
+            "ini": "1.3.4",
+            "minimist": "1.2.0",
+            "strip-json-comments": "2.0.1"
+          },
+          "dependencies": {
+            "minimist": {
+              "version": "1.2.0",
+              "bundled": true,
+              "dev": true,
+              "optional": true
+            }
+          }
+        },
+        "readable-stream": {
+          "version": "2.2.9",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "buffer-shims": "1.0.0",
+            "core-util-is": "1.0.2",
+            "inherits": "2.0.3",
+            "isarray": "1.0.0",
+            "process-nextick-args": "1.0.7",
+            "string_decoder": "1.0.1",
+            "util-deprecate": "1.0.2"
+          }
+        },
+        "request": {
+          "version": "2.81.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "aws-sign2": "0.6.0",
+            "aws4": "1.6.0",
+            "caseless": "0.12.0",
+            "combined-stream": "1.0.5",
+            "extend": "3.0.1",
+            "forever-agent": "0.6.1",
+            "form-data": "2.1.4",
+            "har-validator": "4.2.1",
+            "hawk": "3.1.3",
+            "http-signature": "1.1.1",
+            "is-typedarray": "1.0.0",
+            "isstream": "0.1.2",
+            "json-stringify-safe": "5.0.1",
+            "mime-types": "2.1.15",
+            "oauth-sign": "0.8.2",
+            "performance-now": "0.2.0",
+            "qs": "6.4.0",
+            "safe-buffer": "5.0.1",
+            "stringstream": "0.0.5",
+            "tough-cookie": "2.3.2",
+            "tunnel-agent": "0.6.0",
+            "uuid": "3.0.1"
+          }
+        },
+        "rimraf": {
+          "version": "2.6.1",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "glob": "7.1.2"
+          }
+        },
+        "safe-buffer": {
+          "version": "5.0.1",
+          "bundled": true,
+          "dev": true
+        },
+        "semver": {
+          "version": "5.3.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "set-blocking": {
+          "version": "2.0.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "signal-exit": {
+          "version": "3.0.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "sntp": {
+          "version": "1.0.9",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "hoek": "2.16.3"
+          }
+        },
+        "sshpk": {
+          "version": "1.13.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "asn1": "0.2.3",
+            "assert-plus": "1.0.0",
+            "bcrypt-pbkdf": "1.0.1",
+            "dashdash": "1.14.1",
+            "ecc-jsbn": "0.1.1",
+            "getpass": "0.1.7",
+            "jodid25519": "1.0.2",
+            "jsbn": "0.1.1",
+            "tweetnacl": "0.14.5"
+          },
+          "dependencies": {
+            "assert-plus": {
+              "version": "1.0.0",
+              "bundled": true,
+              "dev": true,
+              "optional": true
+            }
+          }
+        },
+        "string-width": {
+          "version": "1.0.2",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "code-point-at": "1.1.0",
+            "is-fullwidth-code-point": "1.0.0",
+            "strip-ansi": "3.0.1"
+          }
+        },
+        "string_decoder": {
+          "version": "1.0.1",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "safe-buffer": "5.0.1"
+          }
+        },
+        "stringstream": {
+          "version": "0.0.5",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "strip-ansi": {
+          "version": "3.0.1",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "ansi-regex": "2.1.1"
+          }
+        },
+        "strip-json-comments": {
+          "version": "2.0.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "tar": {
+          "version": "2.2.1",
+          "bundled": true,
+          "dev": true,
+          "requires": {
+            "block-stream": "0.0.9",
+            "fstream": "1.0.11",
+            "inherits": "2.0.3"
+          }
+        },
+        "tar-pack": {
+          "version": "3.4.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "debug": "2.6.8",
+            "fstream": "1.0.11",
+            "fstream-ignore": "1.0.5",
+            "once": "1.4.0",
+            "readable-stream": "2.2.9",
+            "rimraf": "2.6.1",
+            "tar": "2.2.1",
+            "uid-number": "0.0.6"
+          }
+        },
+        "tough-cookie": {
+          "version": "2.3.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "punycode": "1.4.1"
+          }
+        },
+        "tunnel-agent": {
+          "version": "0.6.0",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "safe-buffer": "5.0.1"
+          }
+        },
+        "tweetnacl": {
+          "version": "0.14.5",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "uid-number": {
+          "version": "0.0.6",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "util-deprecate": {
+          "version": "1.0.2",
+          "bundled": true,
+          "dev": true
+        },
+        "uuid": {
+          "version": "3.0.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true
+        },
+        "verror": {
+          "version": "1.3.6",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "extsprintf": "1.0.2"
+          }
+        },
+        "wide-align": {
+          "version": "1.1.2",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "string-width": "1.0.2"
+          }
+        },
+        "wrappy": {
+          "version": "1.0.2",
+          "bundled": true,
+          "dev": true
+        }
+      }
+    },
     "function-bind": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/function-bind/-/function-bind-1.1.0.tgz",
@@ -2938,6 +3843,13 @@
       "integrity": "sha1-j7+rsKmKJT0xhDMfno3rc3L6xsA=",
       "dev": true
     },
+    "nan": {
+      "version": "2.8.0",
+      "resolved": "https://registry.npmjs.org/nan/-/nan-2.8.0.tgz",
+      "integrity": "sha1-7XFfP+neArV6XmJS2QqWZ14fCFo=",
+      "dev": true,
+      "optional": true
+    },
     "natural-compare": {
       "version": "1.4.0",
       "resolved": "https://registry.npmjs.org/natural-compare/-/natural-compare-1.4.0.tgz",
diff --git a/src/Persistence.js b/src/Persistence.js
index 3a4e0b11..38766bb9 100644
--- a/src/Persistence.js
+++ b/src/Persistence.js
@@ -17,13 +17,13 @@ export default class AbstractPersistence {
   constructor (opts) {
     this.opts = opts
     this.ys = new Map()
-    this.mutualExclude = createMutualExclude()
   }
 
   _init (y) {
     let cnf = this.ys.get(y)
     if (cnf === undefined) {
       cnf = getFreshCnf()
+      cnf.mutualExclude = createMutualExclude()
       this.ys.set(y, cnf)
       return this.init(y).then(() => {
         y.on('afterTransaction', (y, transaction) => {
@@ -85,7 +85,7 @@ export default class AbstractPersistence {
   saveStruct (y, struct) {
     let cnf = this.ys.get(y)
     if (cnf !== undefined) {
-      this.mutualExclude(function () {
+      cnf.mutualExclude(function () {
         struct._toBinary(cnf.buffer)
         cnf.len++
       })
@@ -94,19 +94,22 @@ export default class AbstractPersistence {
 
   /* overwrite */
   retrieve (y, model, updates) {
-    this.mutualExclude(function () {
-      y.transact(function () {
-        if (model != null) {
-          fromBinary(y, new BinaryDecoder(new Uint8Array(model)))
-        }
-        if (updates != null) {
-          for (let i = 0; i < updates.length; i++) {
-            integrateRemoteStructs(y, new BinaryDecoder(new Uint8Array(updates[i])))
+    let cnf = this.ys.get(y)
+    if (cnf !== undefined) {
+      cnf.mutualExclude(function () {
+        y.transact(function () {
+          if (model != null) {
+            fromBinary(y, new BinaryDecoder(new Uint8Array(model)))
           }
-        }
+          if (updates != null) {
+            for (let i = 0; i < updates.length; i++) {
+              integrateRemoteStructs(y, new BinaryDecoder(new Uint8Array(updates[i])))
+            }
+          }
+        })
+        y.emit('persistenceReady')
       })
-      y.emit('persistenceReady')
-    })
+    }
   }
 
   /* overwrite */