SQL Server Requires Chilkat v11.7.0+

Remove a PDF's Old Revisions

See more PDF Optimization Examples

Demonstrates dropOldRevisions. A PDF that has been edited and saved several times carries every earlier revision: the superseded objects are still in the file, reachable through the older cross-reference sections. The audit reports them as "oldRevisions", and dropping them is often the single largest saving in a real document. Dropping them requires a full rewrite, which is why it invalidates existing digital signatures. SQL Server

--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @success int
    SELECT @success = 0

    --  This example requires the Chilkat API to have been previously unlocked.
    --  See Global Unlock Sample for sample code.

    --  The PDF used in this example is available at grand_canyon_hiking_guide.pdf

    DECLARE @pdf int
    EXEC @hr = sp_OACreate 'Chilkat.Pdf', @pdf OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    EXEC sp_OAMethod @pdf, 'LoadFile', @success OUT, 'qa_data/pdf/grand_canyon_hiking_guide.pdf'
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @pdf, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pdf
        RETURN
      END

    --  How much of this file is superseded revisions?
    DECLARE @json int
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @json OUT

    DECLARE @jsonOut int
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @jsonOut OUT

    EXEC sp_OAMethod @pdf, 'Optimize', @success OUT, 'audit', @json, @jsonOut
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @pdf, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pdf
        EXEC @hr = sp_OADestroy @json
        EXEC @hr = sp_OADestroy @jsonOut
        RETURN
      END


    EXEC sp_OAMethod @jsonOut, 'IntOf', @iTmp0 OUT, 'fileSize'
    PRINT 'fileSize:     ' + @iTmp0

    EXEC sp_OAMethod @jsonOut, 'IntOf', @iTmp0 OUT, 'usage.oldRevisions.bytes'
    PRINT 'oldRevisions: ' + @iTmp0

    --  Drop them, and nothing else, so that the saving is attributable.
    EXEC sp_OAMethod @json, 'UpdateBool', @success OUT, 'compressUncompressed', 0
    EXEC sp_OAMethod @json, 'UpdateBool', @success OUT, 'recompressFlate', 0
    EXEC sp_OAMethod @json, 'UpdateBool', @success OUT, 'replaceLegacyFilters', 0
    EXEC sp_OAMethod @json, 'UpdateBool', @success OUT, 'imagePredictors', 0
    EXEC sp_OAMethod @json, 'UpdateBool', @success OUT, 'dedupeStreams', 0
    EXEC sp_OAMethod @json, 'UpdateBool', @success OUT, 'dedupeObjects', 0
    EXEC sp_OAMethod @json, 'UpdateBool', @success OUT, 'removeUnreferenced', 0
    EXEC sp_OAMethod @json, 'UpdateBool', @success OUT, 'removeUnusedResources', 0
    EXEC sp_OAMethod @json, 'UpdateBool', @success OUT, 'removeUnusedLayers', 0
    EXEC sp_OAMethod @json, 'UpdateBool', @success OUT, 'coalesceContent', 0
    EXEC sp_OAMethod @json, 'UpdateBool', @success OUT, 'tidyContent', 0
    EXEC sp_OAMethod @json, 'UpdateBool', @success OUT, 'subsetFonts', 0
    EXEC sp_OAMethod @json, 'UpdateBool', @success OUT, 'dropOldRevisions', 1

    EXEC sp_OAMethod @pdf, 'Optimize', @success OUT, 'optimize', @json, @jsonOut
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @pdf, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pdf
        EXEC @hr = sp_OADestroy @json
        EXEC @hr = sp_OADestroy @jsonOut
        RETURN
      END

    EXEC sp_OAMethod @pdf, 'WriteFile', @success OUT, 'qa_output/grand_canyon_one_revision.pdf'
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @pdf, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pdf
        EXEC @hr = sp_OADestroy @json
        EXEC @hr = sp_OADestroy @jsonOut
        RETURN
      END

    --  The saving is an estimate: what the old revisions occupied is known exactly, but the writer
    --  decides the final layout.  Measure the written file for the real number.
    DECLARE @fac int
    EXEC @hr = sp_OACreate 'Chilkat.FileAccess', @fac OUT


    EXEC sp_OAMethod @jsonOut, 'IntOf', @iTmp0 OUT, 'bytesSaved'
    PRINT 'bytesSaved (reported): ' + @iTmp0

    EXEC sp_OAMethod @fac, 'FileSize', @iTmp0 OUT, 'qa_output/grand_canyon_one_revision.pdf'
    PRINT 'written file:          ' + @iTmp0

    EXEC @hr = sp_OADestroy @pdf
    EXEC @hr = sp_OADestroy @json
    EXEC @hr = sp_OADestroy @jsonOut
    EXEC @hr = sp_OADestroy @fac


END
GO