From eb3eb615ec798932a8d2aa7119612fe00cc7fcbf Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 12 May 2016 10:26:52 +0530
Subject: [PATCH] Move ReadOnyFileBuffer into its own module

---
 src/calibre/srv/http_response.py |  3 ++-
 src/calibre/srv/utils.py         | 36 -------------------------
 src/calibre/srv/web_socket.py    |  3 ++-
 src/calibre/utils/img.py         |  2 +-
 src/calibre/utils/imghdr.py      |  2 +-
 src/calibre/utils/speedups.py    | 46 ++++++++++++++++++++++++++++++++
 6 files changed, 52 insertions(+), 40 deletions(-)
 create mode 100644 src/calibre/utils/speedups.py

diff --git a/src/calibre/srv/http_response.py b/src/calibre/srv/http_response.py
index dad2464260..a041b1f8c1 100644
--- a/src/calibre/srv/http_response.py
+++ b/src/calibre/srv/http_response.py
@@ -22,7 +22,8 @@ from calibre.srv.http_request import HTTPRequest, read_headers
 from calibre.srv.sendfile import file_metadata, sendfile_to_socket_async, CannotSendfile, SendfileInterrupted
 from calibre.srv.utils import (
     MultiDict, http_date, HTTP1, HTTP11, socket_errors_socket_closed,
-    sort_q_values, get_translator_for_lang, Cookie, ReadOnlyFileBuffer)
+    sort_q_values, get_translator_for_lang, Cookie)
+from calibre.utils.speedups import ReadOnlyFileBuffer
 from calibre.utils.monotonic import monotonic
 
 Range = namedtuple('Range', 'start stop size')
diff --git a/src/calibre/srv/utils.py b/src/calibre/srv/utils.py
index 9ad33cf848..725ef94907 100644
--- a/src/calibre/srv/utils.py
+++ b/src/calibre/srv/utils.py
@@ -434,42 +434,6 @@ class Accumulator(object):  # {{{
         return ans
 # }}}
 
-class ReadOnlyFileBuffer(object):
-
-    ''' A zero copy implementation of a file like object. Uses memoryviews for efficiency. '''
-
-    def __init__(self, raw):
-        self.sz, self.mv = len(raw), (raw if isinstance(raw, memoryview) else memoryview(raw))
-        self.pos = 0
-
-    def tell(self):
-        return self.pos
-
-    def read(self, n=None):
-        if n is None:
-            ans = self.mv[self.pos:]
-            self.pos = self.sz
-            return ans
-        ans = self.mv[self.pos:self.pos+n]
-        self.pos = min(self.pos + n, self.sz)
-        return ans
-
-    def seek(self, pos, whence=os.SEEK_SET):
-        if whence == os.SEEK_SET:
-            self.pos = pos
-        elif whence == os.SEEK_END:
-            self.pos = self.sz + pos
-        else:
-            self.pos += pos
-        self.pos = max(0, min(self.pos, self.sz))
-        return self.pos
-
-    def getvalue(self):
-        return self.mv
-
-    def close(self):
-        pass
-
 def get_db(ctx, rd, library_id):
     db = ctx.get_library(rd, library_id)
     if db is None:
diff --git a/src/calibre/srv/web_socket.py b/src/calibre/srv/web_socket.py
index c12a1b482e..d92cb39349 100644
--- a/src/calibre/srv/web_socket.py
+++ b/src/calibre/srv/web_socket.py
@@ -17,7 +17,8 @@ from calibre import as_unicode
 from calibre.constants import plugins
 from calibre.srv.loop import ServerLoop, HandleInterrupt, WRITE, READ, RDWR, Connection
 from calibre.srv.http_response import HTTPConnection, create_http_handler
-from calibre.srv.utils import DESIRED_SEND_BUFFER_SIZE, ReadOnlyFileBuffer
+from calibre.srv.utils import DESIRED_SEND_BUFFER_SIZE
+from calibre.utils.speedups import ReadOnlyFileBuffer
 speedup, err = plugins['speedup']
 if not speedup:
     raise RuntimeError('Failed to load speedup module with error: ' + err)
diff --git a/src/calibre/utils/img.py b/src/calibre/utils/img.py
index 23c730e2e6..b3cdfcb8ee 100644
--- a/src/calibre/utils/img.py
+++ b/src/calibre/utils/img.py
@@ -437,7 +437,7 @@ def optimize_png(file_path):
     return run_optimizer(file_path, cmd)
 
 def encode_jpeg(file_path, quality=80):
-    from calibre.srv.utils import ReadOnlyFileBuffer
+    from calibre.utils.speedups import ReadOnlyFileBuffer
     quality = max(0, min(100, int(quality)))
     exe = get_exe_path('cjpeg')
     cmd = [exe] + '-optimize -progressive -maxmemory 100M -quality'.split() + [str(quality)]
diff --git a/src/calibre/utils/imghdr.py b/src/calibre/utils/imghdr.py
index 5bea1ae708..d8c827c021 100644
--- a/src/calibre/utils/imghdr.py
+++ b/src/calibre/utils/imghdr.py
@@ -6,7 +6,7 @@ from __future__ import (unicode_literals, division, absolute_import,
                         print_function)
 from struct import unpack, error
 import os
-from calibre.srv.utils import ReadOnlyFileBuffer
+from calibre.utils.speedups import ReadOnlyFileBuffer
 
 """ Recognize image file formats and sizes based on their first few bytes."""
 
diff --git a/src/calibre/utils/speedups.py b/src/calibre/utils/speedups.py
new file mode 100644
index 0000000000..179405a5eb
--- /dev/null
+++ b/src/calibre/utils/speedups.py
@@ -0,0 +1,46 @@
+#!/usr/bin/env python2
+# vim:fileencoding=utf-8
+# License: GPLv3 Copyright: 2016, Kovid Goyal <kovid at kovidgoyal.net>
+
+from __future__ import (unicode_literals, division, absolute_import,
+                        print_function)
+
+import os
+
+class ReadOnlyFileBuffer(object):
+
+    ''' A zero copy implementation of a file like object. Uses memoryviews for efficiency. '''
+
+    def __init__(self, raw):
+        self.sz, self.mv = len(raw), (raw if isinstance(raw, memoryview) else memoryview(raw))
+        self.pos = 0
+
+    def tell(self):
+        return self.pos
+
+    def read(self, n=None):
+        if n is None:
+            ans = self.mv[self.pos:]
+            self.pos = self.sz
+            return ans
+        ans = self.mv[self.pos:self.pos+n]
+        self.pos = min(self.pos + n, self.sz)
+        return ans
+
+    def seek(self, pos, whence=os.SEEK_SET):
+        if whence == os.SEEK_SET:
+            self.pos = pos
+        elif whence == os.SEEK_END:
+            self.pos = self.sz + pos
+        else:
+            self.pos += pos
+        self.pos = max(0, min(self.pos, self.sz))
+        return self.pos
+
+    def getvalue(self):
+        return self.mv
+
+    def close(self):
+        pass
+
+