Recent changes to Thumbnailing

Thumbnailing modified by Adam Tauno Williams

Adam Tauno Williams — Wed, 06 May 2015 16:04:52 -0000

--- v5
+++ v6
@@ -54,6 +54,14 @@
     awilliam@linux-86wr:~> ls -l file.png
     ls: cannot access file.png: No such file or directory

+__Coils Log___
+
+    2015-06-05T14:55:39:context:DEBUG: duration of document::get-handle was 0.081
+    2015-06-05T14:55:39:context:DEBUG: converter completed with exit code 1 for OGo#314232599 [Document]
+    2015-06-05T14:55:39:context:INFO: recording 165b of stderr content from convert for OGo#314232599 [Document] to audit log
+    2015-06-05T14:55:39:context:INFO: stderr content queued for commit
+
+
 ####What does convert look like when it fails to process a PDF?

     ???

Thumbnailing modified by Adam Tauno Williams

Adam Tauno Williams — Wed, 06 May 2015 12:44:49 -0000

--- v4
+++ v5
@@ -43,9 +43,10 @@
     [root@coils-red ~]# rpm -qf /usr/bin/convert
     ImageMagick-6.5.4.7-7.el6_5.x86_64

-What does convert look like when an input document is not a PDF?
+####What does convert look like when an input document is not a PDF?

-    awilliam@linux-86wr:~> cat test.pdf | convert -format pdf -[0] -thumbnail 175x -bordercolor white png:file.png
+    awilliam@linux-86wr:~> cat test.pdf | convert -format pdf -[0] \
+        -thumbnail 175x -bordercolor white png:file.png
     convert: no decode delegate for this image format `/tmp/magick-3499W14ZgJKucF6t' @ error/svg.c/ReadSVGImage/2954.
     convert: no images defined `png:file.png' @ error/convert.c/ConvertImageCommand/3187.
     awilliam@linux-86wr:~> echo $?
@@ -53,13 +54,14 @@
     awilliam@linux-86wr:~> ls -l file.png
     ls: cannot access file.png: No such file or directory

-What does convert look like when it fails to process a PDF?
+####What does convert look like when it fails to process a PDF?

     ???

-What does convert look like when it works?
+####What does convert look like when it works?

-    awilliam@linux-86wr:~> cat Downloads/03-december-2014ridershipproductivityreport.pdf | convert -format pdf -[0] -thumbnail 175x -bordercolor white png:file.png
+    awilliam@linux-86wr:~> cat Downloads/03-december-2014ridershipproductivityreport.pdf \
+      | convert -format pdf -[0] -thumbnail 175x -bordercolor white png:file.png
     awilliam@linux-86wr:~> echo $?
     0
     awilliam@linux-86wr:~> ls -l file.png

Thumbnailing modified by Adam Tauno Williams

Adam Tauno Williams — Wed, 06 May 2015 12:43:52 -0000

--- v3
+++ v4
@@ -42,3 +42,25 @@

     [root@coils-red ~]# rpm -qf /usr/bin/convert
     ImageMagick-6.5.4.7-7.el6_5.x86_64
+
+What does convert look like when an input document is not a PDF?
+
+    awilliam@linux-86wr:~> cat test.pdf | convert -format pdf -[0] -thumbnail 175x -bordercolor white png:file.png
+    convert: no decode delegate for this image format `/tmp/magick-3499W14ZgJKucF6t' @ error/svg.c/ReadSVGImage/2954.
+    convert: no images defined `png:file.png' @ error/convert.c/ConvertImageCommand/3187.
+    awilliam@linux-86wr:~> echo $?
+    1
+    awilliam@linux-86wr:~> ls -l file.png
+    ls: cannot access file.png: No such file or directory
+
+What does convert look like when it fails to process a PDF?
+
+    ???
+
+What does convert look like when it works?
+
+    awilliam@linux-86wr:~> cat Downloads/03-december-2014ridershipproductivityreport.pdf | convert -format pdf -[0] -thumbnail 175x -bordercolor white png:file.png
+    awilliam@linux-86wr:~> echo $?
+    0
+    awilliam@linux-86wr:~> ls -l file.png
+    -rw-r--r-- 1 awilliam users 27715 May  6 08:41 file.png

Thumbnailing modified by Adam Tauno Williams

Adam Tauno Williams — Wed, 06 May 2015 12:39:40 -0000

--- v2
+++ v3
@@ -11,6 +11,7 @@
 ###PDF

 The PDF thumbnailer uses the __convert__ utility provided by ImageMagick to make and image of the first page of the document
+

     signal.signal(signal.SIGALRM, timeout_alarm_handler)
     signal.alarm(CONVERSION_TIMEOUT_SECONDS)
@@ -34,7 +35,8 @@
     converter.communicate()
     signal.alarm(0)

-The problem, as always, with using external executables is untraceable dependencies [think __fonts__] as well as error management.  Did it work?  If not why not.  Is the executable even there?  Is it a good version?
+
+The problem, as always, with using external executables is untraceable dependencies - think __fonts__ - as well as error management.  Did it work?  If not why not.  Is the executable even there?  Is it a good version?

 __Note:__ we expect the OS to provide a sane installation of __convert__.

Thumbnailing modified by Adam Tauno Williams

Adam Tauno Williams — Wed, 06 May 2015 12:38:45 -0000

--- v1
+++ v2
@@ -0,0 +1,42 @@
+#Creating document thumbnails
+
+Performed by the __coils.blob.autothumb__ component which creates a set of workers to perform thumbnailing of documents
+
+##Possible Issues
+
+   - does this correctly serialize multiple updates to a document?  we should try to squeeze out rapid fire events.
+
+##Document Types
+
+###PDF
+
+The PDF thumbnailer uses the __convert__ utility provided by ImageMagick to make and image of the first page of the document
+
+    signal.signal(signal.SIGALRM, timeout_alarm_handler)
+    signal.alarm(CONVERSION_TIMEOUT_SECONDS)
+
+    # convert -format pdf -[0] -thumbnail 175x -bordercolor white png:-
+
+    converter = Popen(
+        [
+            '/usr/bin/convert', '-format', 'pdf', '-[0]',
+            '-thumbnail', '175x', '-bordercolor', 'white', 'png:-',
+        ],
+        stdin=PIPE,
+        stdout=sfile,
+    )
+    (converter_in, converter_out, ) = (
+        converter.stdin, converter.stdout,
+    )
+
+    shutil.copyfileobj(rfile, converter_in)
+    converter_in.close()
+    converter.communicate()
+    signal.alarm(0)
+
+The problem, as always, with using external executables is untraceable dependencies [think __fonts__] as well as error management.  Did it work?  If not why not.  Is the executable even there?  Is it a good version?
+
+__Note:__ we expect the OS to provide a sane installation of __convert__.
+
+    [root@coils-red ~]# rpm -qf /usr/bin/convert
+    ImageMagick-6.5.4.7-7.el6_5.x86_64

Thumbnailing modified by Adam Tauno Williams

Adam Tauno Williams — Wed, 06 May 2015 12:33:36 -0000