use cache in pdf_to_imageHEADmaster

1 files changed, 30 insertions, 14 deletions

diff --git a/web.py b/web.py
index 756d03b..9ce75c4 100644
--- a/web.py
+++ b/web.py
@@ -17,11 +17,13 @@ import whoosh.query as query
 import flask
 import pyPdf
 import werkzeug
+from werkzeug.contrib.cache import SimpleCache
 import subprocess
 from compat import str_format
 
 app = flask.Flask("booksearch")
 app.debug = True
+image_cache = SimpleCache()
 
 index_book = open_dir(u"index", u"book")
 index_metadata = open_dir(u"index", u"metadata")
@@ -47,20 +49,34 @@ def pdf_to_image(filepath, page, size):
     density = 60 + 0.15 * size
     app.logger.debug( str_format("Convert PDF to image page={page} size={size} density={density} filepath={filepath}", page=page, size=size, density=density, filepath=filepath ))
 
-    def generator(process, input):
-        input.seek(0)
-        while not process.stdin.closed:
-            stdout, stderr = process.communicate(input.read())
-            if stdout:
-                yield stdout
-    pdffile = StringIO()
-    page = pyPdf.PdfFileReader(file(filepath, "r")).getPage(page)
-    out = pyPdf.PdfFileWriter()
-    out.addPage(page)
-    out.write(pdffile)
-    process = subprocess.Popen(["/usr/bin/convert", "-density", str(density), "-resize", str(size), "pdf:-", "jpeg:-"],
-        stdin=subprocess.PIPE, stdout=subprocess.PIPE)
-    return werkzeug.Response(generator(process,pdffile), mimetype="image/jpeg")
+    if image_cache.get("PDF_IMAGE_"+str(size)+"_"+str(page)+filepath) is None:
+        try:
+            pdffile = StringIO()
+            page = pyPdf.PdfFileReader(file(filepath, "r")).getPage(page)
+            out = pyPdf.PdfFileWriter()
+            out.addPage(page)
+            out.write(pdffile)
+            pdffile.seek(0)
+            process = subprocess.Popen(["/usr/local/bin/convert", "-density", str(density), "-resize", str(size), "pdf:-", "jpeg:-"],
+                stdin=subprocess.PIPE, stdout=subprocess.PIPE)
+            process.stdin.write(pdffile.read())
+            image_data = ""
+            while not process.stdout.closed:
+                image_data += process.communicate()[0]
+            image_cache.set("PDF_IMAGE_"+str(size)+"_"+str(page)+filepath, image_data)
+        except Exception,e:
+            process = subprocess.Popen(["/usr/local/bin/convert", "-size", str(size), "-fill", "black", "-pointsize", "23", "caption:@-", "jpeg:-"],
+                stdin=subprocess.PIPE, stdout=subprocess.PIPE)
+            message = str_format("Error:\n{error}", error=str(e))
+            if image_cache.get("EXCEPTION_"+ str(size) + message) is None:
+                image_data =""
+                process.stdin.write(message)
+                while not process.stdout.closed:
+                    image_data += process.communicate()[0]
+                image_cache.set("EXCEPTION_" + str(size) + message, image_data, timeout=60*60)
+            return werkzeug.Response(image_cache.get("EXCEPTION_" + str(size) + message), mimetype="image/jpeg")
+       
+    return werkzeug.Response(image_cache.get("PDF_IMAGE_"+str(size)+"_"+str(page)+filepath), mimetype="image/jpeg")
 
 @app.route("/page/image/<int:docnum>", methods=["GET"])
 @app.route("/page/image/<int:docnum>/<int:size>", methods=["GET"])