Zip XML in memory for Web Service transport (SharpZipLib)

Here is a full test program that demonstrates how to use SharpZipLib to zip an XElement into a byte array. This allows you to transfer large XML items over web services, and then unzip then on the web service side. I included two methods to unzip, both back to an XElement and to an XML file. IIS 6 does allow compression as well, but the reason I had to have the functionality below was that a PC client application was required to send a host web service a large set of XML (rather than the host sending the client XML).

using System;
using System.IO;
using System.Xml.Linq;
using ICSharpCode.SharpZipLib.Zip;

namespace ConsoleTest
{
   class Program
   {
      static void Main(string[] args)
      {
         new Program().Run(args);
      }

      private void Run(string[] args)
      {
         // create some xml
         XElement xml = XElement.Parse("<xml><element>whatever</element></xml>");

         // zip xml
         string startXml = xml.ToString();
         byte[] bytes = ZipContent(xml, "TestXML");

         // unzip xml
         xml = UnzipContent(bytes);
         string endXml = xml.ToString();

         // sanity check
         System.Diagnostics.Debug.Assert(startXml == endXml);
      }

      /// <summary>
      /// Convert XML to zipped byte array.
      /// </summary>
      /// <param name="xml">XML to zip.</param>
      /// <param name="entryName">The zip entry name.</param>
      /// <returns>A byte array that contains the xml zipped.</returns>
      private byte[] ZipContent(XElement xml, string entryName)
      {
         // remove whitespace from xml and convert to byte array
         byte[] normalBytes;
         using (StringWriter writer = new StringWriter())
         {
            xml.Save(writer, SaveOptions.DisableFormatting);
            System.Text.ASCIIEncoding encoding = new System.Text.ASCIIEncoding();
            normalBytes = encoding.GetBytes(writer.ToString());
         }

         // zip into new, zipped, byte array
         using (Stream memOutput = new MemoryStream())
         using (ZipOutputStream zipOutput = new ZipOutputStream(memOutput))
         {
            zipOutput.SetLevel(9);

            ZipEntry entry = new ZipEntry(entryName);
            entry.DateTime = DateTime.Now;
            zipOutput.PutNextEntry(entry);

            zipOutput.Write(normalBytes, 0, normalBytes.Length);
            zipOutput.Finish();

            byte[] newBytes = new byte[memOutput.Length];
            memOutput.Seek(0, SeekOrigin.Begin);
            memOutput.Read(newBytes, 0, newBytes.Length);

            zipOutput.Close();

            return newBytes;
         }
      }

      /// <summary>
      /// Return zipped bytes as unzipped XML.
      /// </summary>
      /// <param name="bytes">Zipped content.</param>
      /// <returns>Unzipped XML.</returns>
      private XElement UnzipContent(byte[] bytes)
      {
         // unzip bytes into unzipped byte array
         using (Stream memInput = new MemoryStream(bytes))
         using (ZipInputStream input = new ZipInputStream(memInput))
         {
            ZipEntry entry = input.GetNextEntry();

            byte[] newBytes = new byte[entry.Size];
            int count = input.Read(newBytes, 0, newBytes.Length);
            if (count != entry.Size)
            {
               throw new Exception("Invalid read: " + count);
            }

            // convert bytes to string, then to xml
            string xmlString = System.Text.ASCIIEncoding.ASCII.GetString(newBytes);
            return XElement.Parse(xmlString);
         }
      }

      /// <summary>
      /// Save zipped bytes as unzipped file.
      /// </summary>
      /// <param name="bytes">Zipped content.</param>
      /// <param name="path">File path to save unzipped XML.</param>
      private void UnzipContent(byte[] bytes, string path)
      {
         // unzip bytes into unzipped byte array
         using (Stream memInput = new MemoryStream(bytes))
         using (ZipInputStream zipInput = new ZipInputStream(memInput))
         using (BinaryWriter writer = new BinaryWriter(File.Create(path)))
         {
            ZipEntry entry = zipInput.GetNextEntry();

            int count;
            byte[] input = new byte[1024 * 10];
            while ((count = zipInput.Read(input, 0, input.Length)) > 0)
            {
               writer.Write(input, 0, count);
            }
         }
      }
   }
}

Use PowerShell to capture database schema

Here is a PowerShell script to capture a database schema. Output is written to a directory/datetime file. Multiple databases/servers can be specified via the XML input file.

To run: ./CaptureSchema.ps1 databases.xml

Here is the PowerShell code:

param ([string]$xmlConfig = $(throw '%argument 1 must be XML configuration file path'))

[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.SMO") | out-null
[System.Reflection.Assembly]::LoadWithPartialName("System.Data") | out-null
[System.Reflection.Assembly]::LoadWithPartialName("System.Core") | out-null
[System.Reflection.Assembly]::LoadWithPartialName("System.Linq") | out-null
[System.Reflection.Assembly]::LoadWithPartialName("System.Xml.Linq") | out-null

function ScriptDatabase([string]$serverName, [string]$dbName)
{
   $fileName = [String]::Format("{0} {1}.sql", [DateTime]::Now.ToString("yyyyMMdd_HHmmss"), $dbName)
   [Console]::Write("Server: $serverName, Database: $dbName, Output: `"$fileName`" . . . ")

   $srv = new-object "Microsoft.SqlServer.Management.SMO.Server" $serverName
   $db = new-object "Microsoft.SqlServer.Management.SMO.Database"
   $scr = New-Object "Microsoft.SqlServer.Management.Smo.Scripter"

   $db = $srv.Databases[$dbName]

   $scr.Server = $srv
   $options = New-Object "Microsoft.SqlServer.Management.SMO.ScriptingOptions"
   
   $options.ClusteredIndexes = $true
   $options.Default = $true
   $options.DriAll = $true
   $options.Indexes = $true
   $options.IncludeHeaders = $true
   $options.Triggers = $true
   $options.AppendToFile = $false
   $options.FileName = "$pwd\$fileName"
   $options.ToFileOnly = $true
   
   # output all db tables
   $scr.Options = $options
   $tables = $db.Tables
   if ($tables -ne $null)
   {
      $scr.Script($db.Tables)
   }

   # output all sprocs
   $options.AppendToFile = $true
   $sprocs = $db.StoredProcedures | where {$_.IsSystemObject -eq $false}
   if ($sprocs -ne $null)
   {
      $scr.Script($sprocs)
   }
   
   # output all db views
   $views = $db.Views | where {$_.IsSystemObject -eq $false}
   if ($views -ne $null)
   {
      $scr.Script($views)
   }
   
   "done."
   
}

function SaveSchema($xmlDb)
{
   # make folder if not exists yet
   $dbName = $xmlDb.Element("Name").Value
   $dirName = ".\$dbName"
   if ((Test-Path -path $dirName) -eq $False)
   {
      "Creating directory $dirName..."
      ni -type directory $dirName | out-null
   }
   
   # save the schema
   $serverName = $xmlDb.Element("Server").Value
   
   $prevDir = $pwd
   $prevDir
   set-location $dirName
   ScriptDatabase $serverName $dbName
   set-location $prevDir
}

#
# main
#

$xml = [System.Xml.Linq.XElement]::Load((Resolve-Path "$xmlConfig"))

foreach($db in $xml.Elements("Database"))
{
   if ($db.Attribute("Enabled").Value -eq $true)
   {
      SaveSchema $db
   }
}

exit

Here is the XML input file:

<Databases>
   <Database Enabled="true">
      <Name>DatabaseName</Name>
      <Server>ServerName</Server>
   </Database>
   <!-- repeat the Database element if more
        than one database schema to capture -->
</Databases>