rename SqliteTable -> SqliteDB

[org.ibex.mail.git] / src / org / ibex / mail / SqliteDB.java

diff --git a/src/org/ibex/mail/SqliteDB.java b/src/org/ibex/mail/SqliteDB.java
new file mode 100644 (file)
index 0000000..39acded
--- /dev/null
+++ b/src/org/ibex/mail/SqliteDB.java
@@ -0,0 +1,85 @@
+package org.ibex.mail;
+
+import org.ibex.io.*;
+import org.ibex.mail.protocol.*;
+import org.ibex.util.*;
+import org.ibex.net.*;
+import java.sql.*;
+import java.net.*;
+import java.io.*;
+import java.util.*;
+import java.sql.Timestamp;
+import java.sql.Connection;
+
+public class SqliteDB {
+
+    protected Connection conn;
+    private String filename;
+    private String reapTable;
+    private String reapColumn;
+
+    // check upstream: PRAGMA encoding = "UTF-8"; 
+    // create indices
+    // PRAGMA auto_vacuum=1  (can only be set before any tables are created)
+    // periodic "PRAGMA integrity_check; "?
+
+    public void setCacheSize(int kilobytes) throws SQLException {
+        conn.prepareStatement("PRAGMA cache_size="+Math.ceil(kilobytes/1.5)+";").executeUpdate();
+    }
+
+    public SqliteDB(String filename, String[] tables) {
+        this(filename, tables, false);
+    }
+    public SqliteDB(String filename, String[] tables, boolean fastButDangerous) {
+        this.filename = filename;
+        try {
+            Class.forName("org.sqlite.JDBC");
+            conn = DriverManager.getConnection("jdbc:sqlite:"+filename);
+            for(String s : tables)
+                conn.prepareStatement(s).executeUpdate();
+            conn.prepareStatement("PRAGMA temp_store = MEMORY").executeUpdate();
+            conn.prepareStatement("PRAGMA page_size=4096").executeUpdate();
+            conn.prepareStatement("PRAGMA cache_size=2000").executeUpdate();
+            if (fastButDangerous)
+                conn.prepareStatement("PRAGMA synchronous = OFF").executeUpdate();
+        }
+        catch (SQLException e) { throw new RuntimeException(e); }
+        catch (ClassNotFoundException e) { throw new RuntimeException(e); }
+    }
+
+    protected void reap(String reapTable, String reapColumn) {
+        if (this.reapTable != null || this.reapColumn != null)
+            throw new RuntimeException("reapTable/reapColumn already set");
+        this.reapTable = reapTable;
+        this.reapColumn = reapColumn;
+        if (reapTable != null && reapColumn != null)
+            Main.cron.executeLater(1000 * REAPER_INTERVAL_SECONDS, new Reaper());
+    }
+
+    public static final int REAPER_INTERVAL_SECONDS = 60 * 60;
+
+    private class Reaper implements Runnable {
+        public void run() {
+            try {
+                Log.warn(Reaper.class, filename + " reaping...");
+                long when = System.currentTimeMillis();
+                when -= 5 * 24 * 60 * 60 * 1000;
+                synchronized(SqliteDB.this) {
+                    PreparedStatement ps =
+                        conn.prepareStatement("select count(*) from "+reapTable+" where "+reapColumn+"<?");
+                    ps.setTimestamp(1, new Timestamp(when));
+                    ResultSet rs = ps.executeQuery();
+                    if (rs.next())
+                        Log.warn(Reaper.class, filename + " reaping " + rs.getInt(1) + " entries");
+                    Log.warn(Reaper.class, filename + ": " + "delete from "+reapTable+" where "+reapColumn+"<"+when);
+                    ps = conn.prepareStatement("delete from "+reapTable+" where "+reapColumn+"<?");
+                    ps.setTimestamp(1, new Timestamp(when));
+                    int rows = ps.executeUpdate();
+                    Log.warn(Reaper.class, filename + " done reaping; removed " + rows + " rows");
+                }
+            } catch (Exception e) { Log.error(Reaper.class, e); }
+            Main.cron.executeLater(1000 * REAPER_INTERVAL_SECONDS, this);
+        }
+    }
+
+}