[libpostgresql-jdbc-java] 05/15: Work around a bug in the server's implementation of the copy protocol. It returns command complete immediately upon receiving the EOF marker in a binary copy, potentially before we've issued CopyDone/Fail. Fix this by simply not processing the command complete message until we believe that we are done with the copy as well.

[Emmanuel Bourg]

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ebourg-guest pushed a commit to tag REL8_4_703
in repository libpostgresql-jdbc-java.

commit c79d86830bb5ce75a092177c35068817ad1dcebe
Author: Kris Jurka <books at ejurka.com>
Date:   Tue Aug 31 18:08:20 2010 +0000

    Work around a bug in the server's implementation of the copy
    protocol.  It returns command complete immediately upon receiving
    the EOF marker in a binary copy, potentially before we've issued
    CopyDone/Fail.  Fix this by simply not processing the command
    complete message until we believe that we are done with the copy
    as well.
    
    Issue originally reported by Matthew Wakeling.
---
 org/postgresql/core/PGStream.java                   | 17 ++++++++++++++++-
 org/postgresql/core/VisibleBufferedInputStream.java | 12 +++++++++++-
 org/postgresql/core/v3/QueryExecutorImpl.java       | 21 ++++++++++++++++++++-
 3 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/org/postgresql/core/PGStream.java b/org/postgresql/core/PGStream.java
index 41a2a2e..9b5d113 100644
--- a/org/postgresql/core/PGStream.java
+++ b/org/postgresql/core/PGStream.java
@@ -3,7 +3,7 @@
 * Copyright (c) 2003-2008, PostgreSQL Global Development Group
 *
 * IDENTIFICATION
-*   $PostgreSQL: pgjdbc/org/postgresql/core/PGStream.java,v 1.21 2007/02/28 06:10:59 jurka Exp $
+*   $PostgreSQL: pgjdbc/org/postgresql/core/PGStream.java,v 1.22 2008/01/08 06:56:27 jurka Exp $
 *
 *-------------------------------------------------------------------------
 */
@@ -249,6 +249,21 @@ public class PGStream
     }
 
     /**
+     * Receives a single character from the backend, without
+     * advancing the current protocol stream position.
+     *
+     * @return the character received
+     * @exception IOException if an I/O Error occurs
+     */
+    public int PeekChar() throws IOException
+    {
+        int c = pg_input.peek();
+        if (c < 0)
+            throw new EOFException();
+        return c;
+    }
+
+    /**
      * Receives a single character from the backend
      *
      * @return the character received
diff --git a/org/postgresql/core/VisibleBufferedInputStream.java b/org/postgresql/core/VisibleBufferedInputStream.java
index 0db6523..1843828 100644
--- a/org/postgresql/core/VisibleBufferedInputStream.java
+++ b/org/postgresql/core/VisibleBufferedInputStream.java
@@ -3,7 +3,7 @@
  * Copyright (c) 2006-2008, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgjdbc/org/postgresql/core/VisibleBufferedInputStream.java,v 1.2 2007/12/15 15:32:37 jurka Exp $
+ *   $PostgreSQL: pgjdbc/org/postgresql/core/VisibleBufferedInputStream.java,v 1.3 2008/01/08 06:56:27 jurka Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -77,6 +77,16 @@ public class VisibleBufferedInputStream extends InputStream {
     }
 
     /**
+     * Reads a byte from the buffer without advancing the index pointer.
+     */
+    public int peek() throws IOException {
+        if (ensureBytes(1)) {
+            return buffer[index] & 0xFF;
+        }
+        return -1;
+    }
+
+    /**
      * Reads byte from the buffer without any checks. This method never
      * reads from the underlaying stream.
      * Before calling this method the {@link #ensureBytes} method must
diff --git a/org/postgresql/core/v3/QueryExecutorImpl.java b/org/postgresql/core/v3/QueryExecutorImpl.java
index 0415c2d..547dcac 100644
--- a/org/postgresql/core/v3/QueryExecutorImpl.java
+++ b/org/postgresql/core/v3/QueryExecutorImpl.java
@@ -4,7 +4,7 @@
 * Copyright (c) 2004, Open Cloud Limited.
 *
 * IDENTIFICATION
-*   $PostgreSQL: pgjdbc/org/postgresql/core/v3/QueryExecutorImpl.java,v 1.45.2.1 2009/12/04 19:53:27 jurka Exp $
+*   $PostgreSQL: pgjdbc/org/postgresql/core/v3/QueryExecutorImpl.java,v 1.45.2.2 2009/12/07 22:03:14 jurka Exp $
 *
 *-------------------------------------------------------------------------
 */
@@ -900,6 +900,25 @@ public class QueryExecutorImpl implements QueryExecutor {
         int len;
 
         while( !endReceiving && (block || pgStream.hasMessagePending()) ) {
+
+            // There is a bug in the server's implementation of the copy
+            // protocol.  It returns command complete immediately upon
+            // receiving the EOF marker in the binary protocol,
+            // potentially before we've issued CopyDone.  When we are not
+            // blocking, we don't think we are done, so we hold off on
+            // processing command complete and any subsequent messages
+            // until we actually are done with the copy.
+            //
+            if (!block) {
+                int c = pgStream.PeekChar();
+                if (c == 'C') // CommandComplete
+                {
+                    if (logger.logDebug())
+                        logger.debug(" <=BE CommandStatus, Ignored until CopyDone");
+                    break;
+                }
+            }
+
             int c = pgStream.ReceiveChar();
             switch(c) {
 

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