X-Git-Url: https://code.wpia.club/?p=gigi.git;a=blobdiff_plain;f=src%2Forg%2Fcacert%2Fgigi%2Fdatabase%2FDatabaseConnection.java;h=0be7becdf90093ee8dddfd0693a77256656a9377;hp=bccae86faebb950f1ea82da64aca0e90db8d58b2;hb=4b9842acd7dd0e79de8fc3f88cb8241f9b2f134e;hpb=a0232b6e40e7e09767f0444d24e18bf12dafc362

diff --git a/src/org/cacert/gigi/database/DatabaseConnection.java b/src/org/cacert/gigi/database/DatabaseConnection.java
index bccae86f..0be7becd 100644
--- a/src/org/cacert/gigi/database/DatabaseConnection.java
+++ b/src/org/cacert/gigi/database/DatabaseConnection.java
@@ -14,6 +14,7 @@ import java.util.HashSet;
 import java.util.Map.Entry;
 import java.util.Properties;
 import java.util.StringJoiner;
+import java.util.concurrent.LinkedBlockingDeque;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -21,15 +22,115 @@ import org.cacert.gigi.database.SQLFileManager.ImportType;
 
 public class DatabaseConnection {
 
-    public static final int CURRENT_SCHEMA_VERSION = 6;
+    public static class Link implements AutoCloseable {
+
+        private DatabaseConnection target;
+
+        protected Link(DatabaseConnection target) {
+            this.target = target;
+        }
+
+        @Override
+        public void close() {
+            synchronized (DatabaseConnection.class) {
+                Link i = instances.get(Thread.currentThread());
+                if (i != this) {
+                    throw new Error();
+                }
+                instances.remove(Thread.currentThread());
+                pool.add(target);
+            }
+        }
+
+    }
+
+    public static final int MAX_CACHED_INSTANCES = 3;
+
+    private static class StatementDescriptor {
+
+        String query;
+
+        boolean scrollable;
+
+        int instance;
+
+        PreparedStatement target;
+
+        public StatementDescriptor(String query, boolean scrollable) {
+            this.query = query;
+            this.scrollable = scrollable;
+            this.instance = 0;
+        }
+
+        public synchronized void instanciate(Connection c) throws SQLException {
+            if (scrollable) {
+                target = c.prepareStatement(query, ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
+            } else {
+                target = c.prepareStatement(query, query.startsWith("SELECT ") ? Statement.NO_GENERATED_KEYS : Statement.RETURN_GENERATED_KEYS);
+            }
+
+        }
+
+        public synchronized PreparedStatement getTarget() {
+            return target;
+        }
+
+        public synchronized void increase() {
+            if (target != null) {
+                throw new IllegalStateException();
+            }
+            instance++;
+        }
+
+        @Override
+        public int hashCode() {
+            final int prime = 31;
+            int result = 1;
+            result = prime * result + instance;
+            result = prime * result + ((query == null) ? 0 : query.hashCode());
+            result = prime * result + (scrollable ? 1231 : 1237);
+            return result;
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (obj == null) {
+                return false;
+            }
+            if (getClass() != obj.getClass()) {
+                return false;
+            }
+            StatementDescriptor other = (StatementDescriptor) obj;
+            if (instance != other.instance) {
+                return false;
+            }
+            if (query == null) {
+                if (other.query != null) {
+                    return false;
+                }
+            } else if ( !query.equals(other.query)) {
+                return false;
+            }
+            if (scrollable != other.scrollable) {
+                return false;
+            }
+            return true;
+        }
+
+    }
+
+    public static final int CURRENT_SCHEMA_VERSION = 18;
 
     public static final int CONNECTION_TIMEOUT = 24 * 60 * 60;
 
     private Connection c;
 
-    private HashMap<String, PreparedStatement> statements = new HashMap<String, PreparedStatement>();
+    private HashMap<StatementDescriptor, PreparedStatement> statements = new HashMap<StatementDescriptor, PreparedStatement>();
 
-    HashSet<PreparedStatement> underUse = new HashSet<>();
+    private HashSet<PreparedStatement> underUse = new HashSet<>();
 
     private static Properties credentials;
 
@@ -55,43 +156,37 @@ public class DatabaseConnection {
     }
 
     protected synchronized PreparedStatement prepareInternal(String query) throws SQLException {
+        return prepareInternal(query, false);
+    }
+
+    protected synchronized PreparedStatement prepareInternal(String query, boolean scrollable) throws SQLException {
+
         ensureOpen();
         query = preprocessQuery(query);
-        PreparedStatement statement = statements.get(query);
-        if (statement != null) {
-            if (underUse.add(statement)) {
-                return statement;
+        StatementDescriptor searchHead = new StatementDescriptor(query, scrollable);
+        PreparedStatement statement = null;
+        while (statement == null) {
+            statement = statements.get(searchHead);
+            if (statement == null) {
+                searchHead.instanciate(c);
+                statement = searchHead.getTarget();
+                if (searchHead.instance >= MAX_CACHED_INSTANCES) {
+                    return statement;
+                }
+                underUse.add(statement);
+                statements.put(searchHead, statement);
+            } else if (underUse.contains(statement)) {
+                searchHead.increase();
+                statement = null;
             } else {
-                throw new Error("Statement in Use");
+                underUse.add(statement);
             }
         }
-        statement = c.prepareStatement(query, query.startsWith("SELECT ") ? Statement.NO_GENERATED_KEYS : Statement.RETURN_GENERATED_KEYS);
-        statements.put(query, statement);
-        if (underUse.add(statement)) {
-            return statement;
-        } else {
-            throw new Error("Statement in Use");
-        }
+        return statement;
     }
 
     protected synchronized PreparedStatement prepareInternalScrollable(String query) throws SQLException {
-        ensureOpen();
-        query = preprocessQuery(query);
-        PreparedStatement statement = statements.get("__SCROLLABLE__! " + query);
-        if (statement != null) {
-            if (underUse.add(statement)) {
-                return statement;
-            } else {
-                throw new Error("Statement in Use");
-            }
-        }
-        statement = c.prepareStatement(query, ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
-        statements.put("__SCROLLABLE__! " + query, statement);
-        if (underUse.add(statement)) {
-            return statement;
-        } else {
-            throw new Error("Statement in Use");
-        }
+        return prepareInternal(query, true);
     }
 
     private long lastAction = System.currentTimeMillis();
@@ -111,17 +206,23 @@ public class DatabaseConnection {
         lastAction = System.currentTimeMillis();
     }
 
-    private static DatabaseConnection instance;
+    private static HashMap<Thread, Link> instances = new HashMap<>();
 
-    public static DatabaseConnection getInstance() {
-        if (instance == null) {
-            synchronized (DatabaseConnection.class) {
-                if (instance == null) {
-                    instance = new DatabaseConnection();
-                }
-            }
+    private static LinkedBlockingDeque<DatabaseConnection> pool = new LinkedBlockingDeque<>();
+
+    private static int connCount = 0;
+
+    public static synchronized DatabaseConnection getInstance() {
+        Link l = instances.get(Thread.currentThread());
+        if (l == null) {
+            throw new Error("No database connection allocated");
         }
-        return instance;
+        return l.target;
+    }
+
+    public static synchronized boolean hasInstance() {
+        Link l = instances.get(Thread.currentThread());
+        return l != null;
     }
 
     public static boolean isInited() {
@@ -133,24 +234,24 @@ public class DatabaseConnection {
             throw new Error("Re-initiaizing is forbidden.");
         }
         credentials = conf;
-        int version = 0;
-        try (GigiPreparedStatement gigiPreparedStatement = new GigiPreparedStatement("SELECT version FROM \"schemeVersion\" ORDER BY version DESC LIMIT 1;")) {
-            GigiResultSet rs = gigiPreparedStatement.executeQuery();
-            if (rs.next()) {
-                version = rs.getInt(1);
+        try (Link i = newLink(false)) {
+            int version = 0;
+            try (GigiPreparedStatement gigiPreparedStatement = new GigiPreparedStatement("SELECT version FROM \"schemeVersion\" ORDER BY version DESC LIMIT 1;")) {
+                GigiResultSet rs = gigiPreparedStatement.executeQuery();
+                if (rs.next()) {
+                    version = rs.getInt(1);
+                }
             }
+            if (version == CURRENT_SCHEMA_VERSION) {
+                return; // Good to go
+            }
+            if (version > CURRENT_SCHEMA_VERSION) {
+                throw new Error("Invalid database version. Please fix this.");
+            }
+            upgrade(version);
+        } catch (InterruptedException e) {
+            throw new Error(e);
         }
-        if (version == CURRENT_SCHEMA_VERSION) {
-            return; // Good to go
-        }
-        if (version > CURRENT_SCHEMA_VERSION) {
-            throw new Error("Invalid database version. Please fix this.");
-        }
-        upgrade(version);
-    }
-
-    public void beginTransaction() throws SQLException {
-        c.setAutoCommit(false);
     }
 
     private static void upgrade(int version) {
@@ -158,12 +259,7 @@ public class DatabaseConnection {
             Statement s = getInstance().c.createStatement();
             try {
                 while (version < CURRENT_SCHEMA_VERSION) {
-                    try (InputStream resourceAsStream = DatabaseConnection.class.getResourceAsStream("upgrade/from_" + version + ".sql")) {
-                        if (resourceAsStream == null) {
-                            throw new Error("Upgrade script from version " + version + " was not found.");
-                        }
-                        SQLFileManager.addFile(s, resourceAsStream, ImportType.PRODUCTION);
-                    }
+                    addUpgradeScript(Integer.toString(version), s);
                     version++;
                 }
                 s.addBatch("UPDATE \"schemeVersion\" SET version='" + version + "'");
@@ -180,19 +276,12 @@ public class DatabaseConnection {
         }
     }
 
-    public void commitTransaction() throws SQLException {
-        c.commit();
-        c.setAutoCommit(true);
-    }
-
-    public void quitTransaction() {
-        try {
-            if ( !c.getAutoCommit()) {
-                c.rollback();
-                c.setAutoCommit(true);
+    private static void addUpgradeScript(String version, Statement s) throws Error, IOException, SQLException {
+        try (InputStream resourceAsStream = DatabaseConnection.class.getResourceAsStream("upgrade/from_" + version + ".sql")) {
+            if (resourceAsStream == null) {
+                throw new Error("Upgrade script from version " + version + " was not found.");
             }
-        } catch (SQLException e) {
-            e.printStackTrace();
+            SQLFileManager.addFile(s, resourceAsStream, ImportType.PRODUCTION);
         }
     }
 
@@ -231,19 +320,46 @@ public class DatabaseConnection {
         return ident;
     }
 
-    protected synchronized void returnStatement(PreparedStatement target) {
-        underUse.remove(target);
+    protected synchronized void returnStatement(PreparedStatement target) throws SQLException {
+        if ( !underUse.remove(target)) {
+            target.close();
+        }
+    }
+
+    public synchronized int getNumberOfLockedStatements() {
+        return underUse.size();
     }
 
-    public void lockedStatements(PrintWriter writer) {
+    public synchronized void lockedStatements(PrintWriter writer) {
         writer.println(underUse.size());
         for (PreparedStatement ps : underUse) {
-            for (Entry<String, PreparedStatement> e : statements.entrySet()) {
+            for (Entry<StatementDescriptor, PreparedStatement> e : statements.entrySet()) {
                 if (e.getValue() == ps) {
                     writer.println("<br/>");
-                    writer.println(e.getKey());
+                    writer.println(e.getKey().instance + ":");
+
+                    writer.println(e.getKey().query);
                 }
             }
         }
     }
+
+    public static synchronized Link newLink(boolean readOnly) throws InterruptedException {
+        if (instances.get(Thread.currentThread()) != null) {
+            throw new Error("There is already a connection allocated for this thread.");
+        }
+        if (pool.isEmpty() && connCount < 5) {
+            pool.addLast(new DatabaseConnection());
+            connCount++;
+        }
+        DatabaseConnection conn = pool.takeFirst();
+        try {
+            conn.c.setReadOnly(readOnly);
+        } catch (SQLException e) {
+            throw new Error(e);
+        }
+        Link l = new Link(conn);
+        instances.put(Thread.currentThread(), l);
+        return l;
+    }
 }