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https://issues.apache.org/jira/browse/CURATOR-322?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15268912#comment-15268912
]
ASF GitHub Bot commented on CURATOR-322:
----------------------------------------
Github user alexbrasetvik commented on a diff in the pull request:
https://github.com/apache/curator/pull/147#discussion_r61903424
--- Diff:
curator-framework/src/main/java/org/apache/curator/framework/schema/Schema.java
---
@@ -0,0 +1,229 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.curator.framework.schema;
+
+import com.google.common.base.Preconditions;
+import org.apache.zookeeper.CreateMode;
+import java.util.regex.Pattern;
+
+/**
+ * Represents and documents operations allowed for a given path pattern
+ */
+public class Schema
+{
+ private final Pattern pathRegex;
+ private final String path;
+ private final String documentation;
+ private final DataValidator dataValidator;
+ private final Allowance ephemeral;
+ private final Allowance sequential;
+ private final Schema.Allowance watched;
+ private final boolean canBeDeleted;
+
+ public enum Allowance
+ {
+ CAN,
+ MUST,
+ CANNOT
+ }
+
+ /**
+ * Start a builder for the given path pattern. Note: full path schemas
+ * take precedence over regex path schemas.
+ *
+ * @param path full ZNode path. This schema only applies to an exact
match
+ * @return builder
+ */
+ public static SchemaBuilder builder(String path)
+ {
+ return new SchemaBuilder(null, path);
+ }
+
+ /**
+ * Start a builder for the given path pattern.
+ *
+ * @param pathRegex regex for the path. This schema applies to any
matching paths
+ * @return builder
+ */
+ public static SchemaBuilder builder(Pattern pathRegex)
+ {
+ return new SchemaBuilder(pathRegex, null);
+ }
+
+ Schema(Pattern pathRegex, String path, String documentation,
DataValidator dataValidator, Allowance ephemeral, Allowance sequential,
Allowance watched, boolean canBeDeleted)
+ {
+ Preconditions.checkNotNull((pathRegex != null) || (path != null),
"pathRegex and path cannot both be null");
+ this.pathRegex = pathRegex;
+ this.path = path;
+ this.documentation = Preconditions.checkNotNull(documentation,
"documentation cannot be null");
+ this.dataValidator = Preconditions.checkNotNull(dataValidator,
"dataValidator cannot be null");
+ this.ephemeral = Preconditions.checkNotNull(ephemeral, "ephemeral
cannot be null");
+ this.sequential = Preconditions.checkNotNull(sequential,
"sequential cannot be null");
+ this.watched = Preconditions.checkNotNull(watched, "watched cannot
be null");
+ this.canBeDeleted = canBeDeleted;
+ }
+
+ /**
+ * Validate that this schema allows znode deletion
+ *
+ * @throws SchemaViolation if schema does not allow znode deletion
+ */
+ public void validateDeletion()
+ {
+ if ( !canBeDeleted )
+ {
+ throw new SchemaViolation(this, "Cannot be deleted");
+ }
+ }
+
+ /**
+ * Validate that this schema's watching setting matches
+ *
+ * @param isWatching true if attempt is being made to watch node
+ * @throws SchemaViolation if schema's watching setting does not match
+ */
+ public void validateWatcher(boolean isWatching)
+ {
+ if ( isWatching && (watched == Allowance.CANNOT) )
+ {
+ throw new SchemaViolation(this, "Cannot be watched");
+ }
+
+ if ( !isWatching && (watched == Allowance.MUST) )
+ {
+ throw new SchemaViolation(this, "Must be watched");
+ }
+ }
+
+ /**
+ * Validate that this schema's create mode setting matches and that
the data is valid
+ *
+ * @param mode CreateMode being used
+ * @param data data being set
+ * @throws SchemaViolation if schema's create mode setting does not
match or data is invalid
+ */
+ public void validateCreate(CreateMode mode, byte[] data)
+ {
+ if ( mode.isEphemeral() && (ephemeral == Allowance.CANNOT) )
+ {
+ throw new SchemaViolation(this, "Cannot be ephemeral");
+ }
+
+ if ( !mode.isEphemeral() && (ephemeral == Allowance.MUST) )
+ {
+ throw new SchemaViolation(this, "Must be ephemeral");
+ }
+
+ if ( mode.isSequential() && (sequential == Allowance.CANNOT) )
+ {
+ throw new SchemaViolation(this, "Cannot be sequential");
+ }
+
+ if ( !mode.isSequential() && (sequential == Allowance.MUST) )
+ {
+ throw new SchemaViolation(this, "Must be sequential");
+ }
+
+ validateData(path, data);
+ }
+
+ /**
+ * Validate that this schema validates the data
+ *
+ *
+ * @param path the znode full path
+ * @param data data being set
+ * @throws SchemaViolation if data is invalid
+ */
+ public void validateData(String path, byte[] data)
+ {
+ if ( !dataValidator.isValid(path, data) )
+ {
+ throw new SchemaViolation(this, "Data is not valid");
+ }
+ }
+
+ /**
+ * Return the raw path for this schema. If a full path was used, it is
returned.
+ * If a regex was used, it is returned
+ *
+ * @return path
+ */
+ public String getRawPath()
+ {
+ return (path != null) ? path : pathRegex.pattern();
+ }
+
+ Pattern getPathRegex()
+ {
+ return pathRegex;
+ }
+
+ String getPath()
+ {
+ return path;
+ }
+
+ @Override
+ public boolean equals(Object o)
+ {
+ if ( this == o )
+ {
+ return true;
+ }
+ if ( o == null || getClass() != o.getClass() )
+ {
+ return false;
+ }
+
+ Schema schema = (Schema)o;
+
+ return pathRegex.equals(schema.pathRegex);
--- End diff --
Few things missing here? :)
> Schema support - path validation and documentation
> --------------------------------------------------
>
> Key: CURATOR-322
> URL: https://issues.apache.org/jira/browse/CURATOR-322
> Project: Apache Curator
> Issue Type: New Feature
> Components: Framework
> Affects Versions: 3.1.0
> Reporter: Jordan Zimmerman
> Assignee: Jordan Zimmerman
> Fix For: TBD
>
>
> ZooKeeper applications are heavily dependent on correct usage of paths,
> watchers, ZNode data, etc. Currently, there is no mechanism for validating
> and documenting this. It would be nice to have some kind of schema system
> that allows for this.
> This issue provides several items of functionality: a) ZNode path
> documentation; b) ZNode path validation; c) keyed reference to ZNode paths.
> Both items are defined in a new class, Schema. A Curator Schema specifies a
> ZNode path (or regex pattern), documentation for that path, and the
> operations that are allowed on that path. Additionally, a set of Schema
> objects are collected into a SchemaSet object that allows any Schema (and
> thereby its path) to be retrieved via a symbolic name. This should make path
> management in ZK applications easier. Lastly, a utility is provided to load
> SchemaSets from a file/stream in JSON format.
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