Simplify loading of javascript in render iframe

Also improves performance by in-lining javascript into index.html

.gitignore

@@ -20,8 +20,7 @@ resources/builtin_recipes.zip
 resources/template-functions.json
 resources/editor-functions.json
 resources/user-manual-translation-stats.json
-resources/content-server/main.js
-resources/content-server/iframe.js
+resources/content-server/index-generated.html
 resources/content-server/locales.zip
 resources/mozilla-ca-certs.pem
 icons/icns/*.iconset

resources/content-server/index.html

@@ -6,8 +6,6 @@
         <meta name="robots" content="noindex">
         <meta name="viewport" content="width=device-width, initial-scale=1">
         <link rel="icon" type="image/png" href="favicon.png">
-        <script>window.calibre_entry_point = 'ENTRY_POINT'; window.calibre_default_library = DEFAULT_LIBRARY;</script>
-        <script type="text/javascript" src="static/main.js"></script>
         <link rel="stylesheet" href="static/reset.css"></link>
         <link rel="stylesheet" href="static/font-awesome/fa.css"></link>
     </head>
@@ -15,7 +13,7 @@
         <div id="page_load_progress">
             <progress>
             </progress>
-            <div>LOADING_MSG&hellip;<div>
+            <div>Loading, please wait&hellip;<div>
             <style type="text/css">
 #page_load_progress {
     position:relative;
@@ -25,5 +23,6 @@
 }
             </style>
         </div>
+    <script id="main_js">MAIN_JS</script>
     </body>
 </html>

src/calibre/srv/code.py

@@ -4,12 +4,10 @@
 
 from __future__ import (unicode_literals, division, absolute_import,
                         print_function)
-import re, hashlib, random, zipfile
-from functools import partial
-from threading import Lock
-from json import load as load_json_file, dumps as json_dumps
+import hashlib, random, zipfile
+from json import load as load_json_file
 
-from calibre import prepare_string_for_xml, as_unicode
+from calibre import as_unicode
 from calibre.customize.ui import available_input_formats
 from calibre.db.view import sanitize_sort_field_name
 from calibre.srv.ajax import search_result
@@ -22,45 +20,18 @@ from calibre.utils.icu import sort_key
 from calibre.utils.localization import get_lang
 from calibre.utils.search_query_parser import ParseException
 
-html_cache = {}
-cache_lock = Lock()
-autoreload_js = None
 POSTABLE = frozenset({'GET', 'POST', 'HEAD'})
 
-def get_html(name, auto_reload_port, **replacements):
-    global autoreload_js
-    key = (name, auto_reload_port, tuple(replacements.iteritems()))
-    with cache_lock:
-        try:
-            return html_cache[key]
-        except KeyError:
-            with lopen(P(name), 'rb') as f:
-                raw = f.read()
-            for k, val in key[-1]:
-                if isinstance(val, type('')):
-                    val = val.encode('utf-8')
-                if isinstance(k, type('')):
-                    k = k.encode('utf-8')
-                raw = raw.replace(k, val)
-            if auto_reload_port > 0:
-                if autoreload_js is None:
-                    autoreload_js = P('content-server/autoreload.js', data=True, allow_user_override=False).replace(
-                        b'AUTORELOAD_PORT', bytes(str(auto_reload_port)))
-                raw = re.sub(
-                    br'(<\s*/\s*head\s*>)', br'<script type="text/javascript">%s</script>\1' % autoreload_js,
-                    raw, flags=re.IGNORECASE)
-            html_cache[key] = raw
-            return raw
-
 @endpoint('', auth_required=False)
 def index(ctx, rd):
-    default_library = ctx.library_info(rd)[1]
-    return rd.generate_static_output('/', partial(
-        get_html, 'content-server/index.html', getattr(rd.opts, 'auto_reload_port', 0),
-        ENTRY_POINT='book list',
-        LOADING_MSG=prepare_string_for_xml(_('Loading library, please wait')),
-        DEFAULT_LIBRARY=json_dumps(default_library)
-    ))
+    return lopen(P('content-server/index-generated.html'), 'rb')
+
+@endpoint('/auto-reload', auth_required=False)
+def auto_reload(ctx, rd):
+    auto_reload_port = getattr(rd.opts, 'auto_reload_port', 0)
+    if auto_reload_port > 0:
+        rd.outheaders.set('Calibre-Auto-Reload-Port', type('')(auto_reload_port), replace_all=True)
+    return lopen(P('content-server/autoreload.js'), 'rb')
 
 def get_basic_query_data(ctx, rd):
     db, library_id, library_map, default_library = get_library_data(ctx, rd)

src/calibre/utils/rapydscript.py

@@ -6,7 +6,7 @@ from __future__ import (unicode_literals, division, absolute_import,
 __license__ = 'GPL v3'
 __copyright__ = '2015, Kovid Goyal <kovid at kovidgoyal.net>'
 
-import os, sys, atexit, errno, subprocess, glob, shutil, json, hashlib, re
+import os, sys, atexit, errno, subprocess, glob, shutil, json, re
 from io import BytesIO
 from threading import local
 from functools import partial
@@ -105,17 +105,13 @@ def compile_srv():
     with lopen(rb, 'rb') as f:
         rv = str(int(re.search(br'^RENDER_VERSION\s+=\s+(\d+)', f.read(), re.M).group(1)))
     base = P('content-server', allow_user_override=False)
-    fname = os.path.join(rapydscript_dir, 'reader.pyj')
-    with lopen(fname, 'rb') as f:
-        reader = compile_pyj(f.read(), fname)
-    sha = hashlib.sha1(reader).hexdigest()
-    with lopen(os.path.join(base, 'iframe.js'), 'wb') as f:
-        f.write(reader.encode('utf-8'))
     fname = os.path.join(rapydscript_dir, 'srv.pyj')
     with lopen(fname, 'rb') as f:
-        raw = compile_pyj(f.read(), fname).replace("__IFRAME_SCRIPT_HASH__", sha).replace('__RENDER_VERSION__', rv)
-    with lopen(os.path.join(base, 'main.js'), 'wb') as f:
-        f.write(raw.encode('utf-8'))
+        js = compile_pyj(f.read(), fname).replace('__RENDER_VERSION__', rv).encode('utf-8')
+    with lopen(os.path.join(base, 'index.html'), 'rb') as f:
+        html = f.read().replace(b'MAIN_JS', js)
+    with lopen(os.path.join(base, 'index-generated.html'), 'wb') as f:
+        f.write(html)
 
 # }}}
 

src/pyj/read_book/db.pyj

@@ -1,7 +1,6 @@
 # vim:fileencoding=utf-8
 # License: GPL v3 Copyright: 2016, Kovid Goyal <kovid at kovidgoyal.net>
 
-from ajax import ajax
 from gettext import gettext as _
 from utils import base64encode, base64decode
 
@@ -24,17 +23,14 @@ def get_error_details(event):
     elif desc.errorCode:
         desc = desc.errorCode
 
-IFRAME_SCRIPT_HASH = "__IFRAME_SCRIPT_HASH__"
-
 DB_NAME = 'calibre-books-db-testing'  # TODO: Remove test suffix and change version back to 1
 DB_VERSION = 1
 
 class DB:
 
-    def __init__(self, idb, ui, supports_blobs, iframe_script):
+    def __init__(self, idb, ui, supports_blobs):
         self.interface_data = ui.interface_data
         self.idb = idb
-        self.iframe_script = iframe_script
         self.supports_blobs = supports_blobs
         if not supports_blobs:
             print('IndexedDB does not support Blob storage, using base64 encoding instead')
@@ -192,29 +188,9 @@ def create_db(ui, interface_data):
             req = idb.transaction(['files'], 'readwrite').objectStore('files').put(blob, ':-test-blob-:')
         except Exception:
             print('WARNING: browser does not support blob storage, calibre falling back to base64 encoding')
-            create_db_stage2(idb, ui, interface_data, False)
-            return
+            return ui.db_initialized(DB(idb, ui, False))
         req.onsuccess = def(event):
-            create_db_stage2(idb, ui, interface_data, True)
+            ui.db_initialized(DB(idb, ui, True))
         req.onerror = def(event):
             print('WARNING: browser does not support blob storage, calibre falling back to base64 encoding')
-            create_db_stage2(idb, ui, interface_data, False)
-
-def create_db_stage2(idb, ui, interface_data, supports_blobs):
-    req = idb.transaction(['objects']).objectStore('objects').get('iframe.js')
-    req.onerror = def(event):
-        ui.db_initialized(_('Failed to initialize books database: ') + get_error_details(event))
-    req.onsuccess = def(event):
-        s = event.result
-        if s and s.script_hash is IFRAME_SCRIPT_HASH:
-            return ui.db_initialized(DB(idb, ui, supports_blobs, s.src))
-        ajax('static/iframe.js', def(end_type, xhr, event):
-            if end_type != 'load':
-                return ui.db_initialized('<div>' + _('Failed to load book reader script') + '</div>' + xhr.error_html)
-            obj = {'key':'iframe.js', 'script_hash': IFRAME_SCRIPT_HASH, 'src':xhr.responseText}
-            req = idb.transaction(['objects'], 'readwrite').objectStore('objects').put(obj)
-            req.onerror = def(event):
-                ui.db_initialized(_('Failed to store book reader script in database: ') + get_error_details(event))
-            req.onsuccess = def(event):
-                ui.db_initialized(DB(idb, ui, supports_blobs, obj.src))
-        ).send()
+            ui.db_initialized(DB(idb, ui, False))

src/pyj/read_book/ui.pyj

@@ -93,8 +93,6 @@ class ReadUI:
 
     def db_initialized(self, db):
         self.db = db
-        if type(self.db) is not 'string':
-            self.view.create_src_doc(self.db.iframe_script)
         if self.pending_load is not None:
             pl, self.pending_load = self.pending_load, None
             self.start_load(*pl)

src/pyj/read_book/view.pyj

@@ -11,13 +11,13 @@ LOADING_DOC = '''
 <head>
 <script type="text/javascript" id="bootstrap" data-key="__KEY__">
 __SCRIPT__
-</script>
+end_script
 </head>
 <body>
 __BS__
 </body>
 </html>
-'''
+'''.replace('end_script', '<' + '/script>')  # cannot have a closing script tag as this is embedded inside a script tag in index.html
 
 class View:
 
@@ -35,13 +35,16 @@ class View:
         self.src_doc = None
         self.iframe_ready = False
         self.pending_spine_load = None
+        self.create_src_doc()
         window.addEventListener('message', self.handle_message.bind(self), False)
 
     @property
     def iframe(self):
         return document.getElementById(iframe_id)
 
-    def create_src_doc(self, iframe_script):
+    def create_src_doc(self):
+        iframe_script = self.ui.interface_data.main_js.replace(/is_running_in_iframe\s*=\s*false/, 'is_running_in_iframe = true')
+        self.ui.interface_data.main_js = None
         self.src_doc = self.iframe.srcdoc = LOADING_DOC.replace(
             '__SCRIPT__', iframe_script).replace(
             '__BS__', _('Bootstrapping book reader...')).replace(

src/pyj/reader.pyj

@@ -1,5 +0,0 @@
-# vim:fileencoding=utf-8
-# License: GPL v3 Copyright: 2016, Kovid Goyal <kovid at kovidgoyal.net>
-
-from read_book.iframe import init
-init()

src/pyj/srv.pyj

@@ -9,16 +9,22 @@ from utils import parse_url_params
 
 from book_list.boss import Boss
 from book_list.globals import set_session_data
+from read_book.iframe import init
 
 def on_library_loaded(end_type, xhr, ev):
     p = document.getElementById('page_load_progress')
     p.parentNode.removeChild(p)
     if end_type is 'load':
         interface_data = JSON.parse(xhr.responseText)
+        interface_data.main_js = main_js
+        script = document.getElementById('main_js')
+        if script:
+            script.parentNode.removeChild(script)  # Free up some memory
         if interface_data.translations:
             install(interface_data.translations)
-        sd = UserSessionData(interface_data['username'], interface_data['user_session_data'])
+        sd = UserSessionData(interface_data.username, interface_data.user_session_data)
         set_session_data(sd)
+        sd.set('library_id', interface_data.library_id)
         Boss(interface_data)
     else:
         p = E.p(style='color:red; font-weight: bold; font-size:1.5em')
@@ -36,25 +42,36 @@ def on_library_load_progress(loaded, total):
 def load_book_list():
     temp = UserSessionData(None, {})  # So that settings for anonymous users are preserved
     query = {}
-    default_lib = window.calibre_default_library
-    v'delete window.calibre_default_library'
-    query.sort = temp.get_library_option(default_lib, 'sort')
     library_id = temp.get('library_id')
     if library_id:
         query.library_id = library_id
+        query.sort = temp.get_library_option(library_id, 'sort')
     url_query = parse_url_params()
     for key in url_query:
         query[key] = url_query[key]
     ajax('interface-data/init', on_library_loaded, on_library_load_progress, query=query).send()
 
 def on_load():
-    ep = window.calibre_entry_point
-    v'delete window.calibre_entry_point'
-    if ep is 'book list':
     print('calibre loaded at:', Date().toString())
     load_book_list()
 
-# We wait for all page elements to load, since this is a single page app
-# with a largely empty starting document, we can use this to preload any resources
-# we know are going to be needed immediately.
-window.addEventListener('load', on_load)
+is_running_in_iframe = False  # Changed before script is loaded in the iframe
+
+if is_running_in_iframe:
+    init()
+else:
+    main_js = document.scripts[0].textContent
+    # We wait for all page elements to load, since this is a single page app
+    # with a largely empty starting document, we can use this to preload any resources
+    # we know are going to be needed immediately.
+    window.addEventListener('load', on_load)
+
+    ajax('auto-reload', def(end_type, xhr, event):
+        if end_type is 'load':
+            port = xhr.getResponseHeader('Calibre-Auto-Reload-Port')
+            if port:
+                src = xhr.responseText.replace('AUTORELOAD_PORT', port)
+                eval(src)
+    , bypass_cache=False).send()
+
+