start work on font usage stats collector

src/calibre/ebooks/oeb/polish/stats.py

@@ -0,0 +1,99 @@
+#!/usr/bin/env python
+# vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:fdm=marker:ai
+from __future__ import (unicode_literals, division, absolute_import,
+                        print_function)
+
+__license__   = 'GPL v3'
+__copyright__ = '2013, Kovid Goyal <kovid at kovidgoyal.net>'
+__docformat__ = 'restructuredtext en'
+
+import json
+
+from PyQt4.Qt import (QWebPage, pyqtProperty, QString, QEventLoop, QWebView,
+                      Qt, QSize, QTimer)
+
+from calibre.ebooks.oeb.display.webview import load_html
+from calibre.gui2 import must_use_qt
+
+class Page(QWebPage):
+
+    def __init__(self, log):
+        self.log = log
+        QWebPage.__init__(self)
+
+    def javaScriptConsoleMessage(self, msg, lineno, msgid):
+        self.log(u'JS:', unicode(msg))
+
+    def javaScriptAlert(self, frame, msg):
+        self.log(unicode(msg))
+
+    def shouldInterruptJavaScript(self):
+        return False
+
+    def _pass_json_value_getter(self):
+        val = json.dumps(self.bridge_value)
+        return QString(val)
+
+    def _pass_json_value_setter(self, value):
+        self.bridge_value = json.loads(unicode(value))
+
+    _pass_json_value = pyqtProperty(QString, fget=_pass_json_value_getter,
+            fset=_pass_json_value_setter)
+
+class StatsCollector(object):
+
+    def __init__(self, container):
+        self.container = container
+        self.log = self.logger = container.log
+        must_use_qt()
+
+        self.loop = QEventLoop()
+        self.view = QWebView()
+        self.page = Page(self.log)
+        self.view.setPage(self.page)
+        self.page.setViewportSize(QSize(1200, 1600))
+
+        self.view.loadFinished.connect(self.collect,
+                type=Qt.QueuedConnection)
+
+        self.render_queue = list(container.spine_items)
+        self.font_stats = {}
+
+        QTimer.singleShot(0, self.render_book)
+
+        if self.loop.exec_() == 1:
+            raise Exception('Failed to gather statistics from book, see log for details')
+
+    def render_book(self):
+        try:
+            if not self.render_queue:
+                self.loop.exit()
+            else:
+                self.render_next()
+        except:
+            self.logger.exception('Rendering failed')
+            self.loop.exit(1)
+
+    def render_next(self):
+        item = unicode(self.render_queue.pop(0))
+        self.current_item = item
+        load_html(item, self.view)
+
+    def collect(self, ok):
+        if not ok:
+            self.log.error('Failed to render document: %s'%self.container.relpath(self.current_item))
+            self.loop.exit(1)
+            return
+        try:
+            self.collect_font_stats()
+        except:
+            self.log.exception('Failed to collect font stats from: %s'%self.container.relpath(self.current_item))
+            self.loop.exit(1)
+            return
+
+        self.render_book()
+
+    def collect_font_stats(self):
+        pass
+
+