Use cached short names in place of long prepared statement names

This allows for prepared statement names of any length.  In particular
it lets one safely use the SQL query itself as the name.

Author: bdowning

lib/connection.js

@@ -19,6 +19,8 @@ var Connection = function(config) {
   this.parsedStatements = {};
   this.writer = new Writer();
   this.ssl = config.ssl || false;
+  this.longNameI = 0;
+  this.longNameMap = {};
   this._ending = false;
   this._mode = TEXT_MODE;
   this._emitMessage = false;
@@ -189,6 +191,15 @@ Connection.prototype.query = function(text) {
   this.stream.write(this.writer.addCString(text).flush(0x51));
 };
 
+Connection.prototype.getShortName = function(longName) {
+  var shortName = this.longNameMap[longName];
+  if (!shortName) {
+    shortName = '__node_pg_short_name_' + (++this.longNameI) + '__';
+    this.longNameMap[longName] = shortName;
+  }
+  return shortName;
+};
+
 //send parse message
 //"more" === true to buffer the message until flush() is called
 Connection.prototype.parse = function(query, more) {
@@ -198,12 +209,16 @@ Connection.prototype.parse = function(query, more) {
   //   types: ['int8', 'bool'] }
 
   //normalize missing query names to allow for null
-  query.name = query.name || '';
+  var query_name = query.name || '';
+  //shorten long (>63 character) names
+  if (query_name.length > 63) {
+    query_name = this.getShortName(query_name);
+  }
   //normalize null type array
   query.types = query.types || [];
   var len = query.types.length;
   var buffer = this.writer
-    .addCString(query.name) //name of query
+    .addCString(query_name) //name of query
     .addCString(query.text) //actual query text
     .addInt16(len);
   for(var i = 0; i < len; i++) {
@@ -220,7 +235,11 @@ Connection.prototype.bind = function(config, more) {
   //normalize config
   config = config || {};
   config.portal = config.portal || '';
-  config.statement = config.statement || '';
+  var config_statement = config.statement || '';
+  //shorten long (>63 character) names
+  if (config_statement.length > 63) {
+    config_statement = this.getShortName(config_statement);
+  }
   config.binary = config.binary || false;
   var values = config.values || [];
   var len = values.length;
@@ -229,7 +248,7 @@ Connection.prototype.bind = function(config, more) {
     useBinary |= values[j] instanceof Buffer;
   var buffer = this.writer
     .addCString(config.portal)
-    .addCString(config.statement);
+    .addCString(config_statement);
   if (!useBinary)
     buffer.addInt16(0);
   else {

lib/native/index.js

@@ -36,6 +36,8 @@ var Client = module.exports = function(config) {
 
   //a hash to hold named queries
   this.namedQueries = {};
+  this.longNameI = 0;
+  this.longNameMap = {};
 };
 
 util.inherits(Client, EventEmitter);
@@ -191,3 +193,12 @@ Client.prototype.setTypeParser = function(oid, format, parseFn) {
 Client.prototype.getTypeParser = function(oid, format) {
   return this._types.getTypeParser(oid, format);
 };
+
+Client.prototype.getShortName = function(longName) {
+  var shortName = this.longNameMap[longName];
+  if (!shortName) {
+    shortName = '__node_pg_native_short_name_' + (++this.longNameI) + '__';
+    this.longNameMap[longName] = shortName;
+  }
+  return shortName;
+};

lib/native/query.js

@@ -86,17 +86,21 @@ NativeQuery.prototype.submit = function(client) {
   //named query
   if(this.name) {
     var values = (this.values||[]).map(utils.prepareValue);
+    var this_name = this.name;
+    if(this_name.length > 63) {
+      this_name = client.getShortName(this_name);
+    }
 
     //check if the client has already executed this named query
     //if so...just execute it again - skip the planning phase
-    if(client.namedQueries[this.name]) {
-      return this.native.execute(this.name, values, after);
+    if(client.namedQueries[this_name]) {
+      return this.native.execute(this_name, values, after);
     }
     //plan the named query the first time, then execute it
-    return this.native.prepare(this.name, this.text, values.length, function(err) {
+    return this.native.prepare(this_name, this.text, values.length, function(err) {
       if(err) return after(err);
-      client.namedQueries[self.name] = true;
-      return self.native.execute(self.name, values, after);
+      client.namedQueries[this_name] = true;
+      return self.native.execute(this_name, values, after);
     });
   }
   else if(this.values) {