diff --git a/config.sample b/config.sample
index d314891..14579da 100644
--- a/config.sample
+++ b/config.sample
@@ -12,6 +12,12 @@
 ; Optional cache directory. Default: /tmp/supysonic
 cache_dir = /var/supysonic/cache
 
+; Main cache max size in MB. Default: 512
+cache_size = 512
+
+; Transcode cache max size in MB. Default: 1024 (1GB)
+transcode_cache_size = 1024
+
 ; Optional rotating log file. Default: none
 log_file = /var/supysonic/supysonic.log
 
diff --git a/setup.py b/setup.py
index 60b6584..79416a8 100755
--- a/setup.py
+++ b/setup.py
@@ -22,6 +22,7 @@ reqs = [
     'Pillow',
     'requests>=1.0.0',
     'mutagen>=1.33',
+    'scandir<2.0.0',
     'zipstream'
 ]
 extras = {
diff --git a/supysonic/api/media.py b/supysonic/api/media.py
index 3749d36..be02879 100644
--- a/supysonic/api/media.py
+++ b/supysonic/api/media.py
@@ -15,6 +15,10 @@ import requests
 import shlex
 import subprocess
 import uuid
+import io
+import hashlib
+import json
+import zlib
 
 from flask import request, Response, send_file
 from flask import current_app
@@ -25,6 +29,7 @@ from zipfile import ZIP_DEFLATED
 from zipstream import ZipFile
 
 from .. import scanner
+from ..cache import CacheMiss
 from ..db import Track, Album, Artist, Folder, User, ClientPrefs, now
 from ..py23 import dict
 
@@ -78,50 +83,59 @@ def stream_media():
         dst_mimetype = mimetypes.guess_type('dummyname.' + dst_suffix, False)[0] or 'application/octet-stream'
 
     if format != 'raw' and (dst_suffix != src_suffix or dst_bitrate != res.bitrate):
-        config = current_app.config['TRANSCODING']
-        transcoder = config.get('transcoder_{}_{}'.format(src_suffix, dst_suffix))
-        decoder = config.get('decoder_' + src_suffix) or config.get('decoder')
-        encoder = config.get('encoder_' + dst_suffix) or config.get('encoder')
-        if not transcoder and (not decoder or not encoder):
-            transcoder = config.get('transcoder')
-            if not transcoder:
-                message = 'No way to transcode from {} to {}'.format(src_suffix, dst_suffix)
-                logger.info(message)
-                raise GenericError(message)
+        # Requires transcoding
+        cache = current_app.transcode_cache
+        cache_key = "{}-{}.{}".format(res.id, dst_bitrate, dst_suffix)
 
-        transcoder, decoder, encoder = map(lambda x: prepare_transcoding_cmdline(x, res.path, src_suffix, dst_suffix, dst_bitrate), [ transcoder, decoder, encoder ])
         try:
-            if transcoder:
-                dec_proc = None
-                proc = subprocess.Popen(transcoder, stdout = subprocess.PIPE)
-            else:
-                dec_proc = subprocess.Popen(decoder, stdout = subprocess.PIPE)
-                proc = subprocess.Popen(encoder, stdin = dec_proc.stdout, stdout = subprocess.PIPE)
-        except OSError:
-            raise ServerError('Error while running the transcoding process')
+            response = send_file(cache.get(cache_key), mimetype=dst_mimetype, conditional=True)
+        except CacheMiss:
+            config = current_app.config['TRANSCODING']
+            transcoder = config.get('transcoder_{}_{}'.format(src_suffix, dst_suffix))
+            decoder = config.get('decoder_' + src_suffix) or config.get('decoder')
+            encoder = config.get('encoder_' + dst_suffix) or config.get('encoder')
+            if not transcoder and (not decoder or not encoder):
+                transcoder = config.get('transcoder')
+                if not transcoder:
+                    message = 'No way to transcode from {} to {}'.format(src_suffix, dst_suffix)
+                    logger.info(message)
+                    raise GenericError(message)
 
-        def transcode():
+            transcoder, decoder, encoder = map(lambda x: prepare_transcoding_cmdline(x, res.path, src_suffix, dst_suffix, dst_bitrate), [ transcoder, decoder, encoder ])
             try:
-                while True:
-                    data = proc.stdout.read(8192)
-                    if not data:
-                        break
-                    yield data
-            except: # pragma: nocover
-                if dec_proc != None:
-                    dec_proc.kill()
-                proc.kill()
+                if transcoder:
+                    dec_proc = None
+                    proc = subprocess.Popen(transcoder, stdout = subprocess.PIPE)
+                else:
+                    dec_proc = subprocess.Popen(decoder, stdout = subprocess.PIPE)
+                    proc = subprocess.Popen(encoder, stdin = dec_proc.stdout, stdout = subprocess.PIPE)
+            except OSError:
+                raise ServerError('Error while running the transcoding process')
 
-            if dec_proc != None:
-                dec_proc.wait()
-            proc.wait()
+            def transcode():
+                try:
+                    while True:
+                        data = proc.stdout.read(8192)
+                        if not data:
+                            break
+                        yield data
+                except: # pragma: nocover
+                    if dec_proc != None:
+                        dec_proc.kill()
+                    proc.kill()
+                    raise
+                finally:
+                    if dec_proc != None:
+                        dec_proc.wait()
+                    proc.wait()
+            resp_content = cache.set_generated(cache_key, transcode)
 
-        logger.info('Transcoding track {0.id} for user {1.id}. Source: {2} at {0.bitrate}kbps. Dest: {3} at {4}kbps'.format(res, request.user, src_suffix, dst_suffix, dst_bitrate))
-        response = Response(transcode(), mimetype = dst_mimetype)
-        if estimateContentLength == 'true':
-            response.headers.add('Content-Length', dst_bitrate * 1000 * res.duration // 8)
+            logger.info('Transcoding track {0.id} for user {1.id}. Source: {2} at {0.bitrate}kbps. Dest: {3} at {4}kbps'.format(res, request.user, src_suffix, dst_suffix, dst_bitrate))
+            response = Response(resp_content, mimetype=dst_mimetype)
+            if estimateContentLength == 'true':
+                response.headers.add('Content-Length', dst_bitrate * 1000 * res.duration // 8)
     else:
-        response = send_file(res.path, mimetype = dst_mimetype, conditional=True)
+        response = send_file(res.path, mimetype=dst_mimetype, conditional=True)
 
     res.play_count = res.play_count + 1
     res.last_play = now()
@@ -159,6 +173,7 @@ def download_media():
 
 @api.route('/getCoverArt.view', methods = [ 'GET', 'POST' ])
 def cover_art():
+    cache = current_app.cache
     eid = request.values['id']
     if Folder.exists(id=eid):
         res = get_entity(Folder)
@@ -166,18 +181,15 @@ def cover_art():
             raise NotFound('Cover art')
         cover_path = os.path.join(res.path, res.cover_art)
     elif Track.exists(id=eid):
-        embed_cache = os.path.join(current_app.config['WEBAPP']['cache_dir'], 'embeded_art')
-        cover_path = os.path.join(embed_cache, eid)
-        if not os.path.exists(cover_path):
+        cache_key = "{}-cover".format(eid)
+        try:
+            cover_path = cache.get(cache_key)
+        except CacheMiss:
             res = get_entity(Track)
             art = res.extract_cover_art()
             if not art:
                 raise NotFound('Cover art')
-            #Art found, save to cache
-            if not os.path.exists(embed_cache):
-                os.makedirs(embed_cache)
-            with open(cover_path, 'wb') as cover_file:
-                cover_file.write(art)
+            cover_path = cache.set(cache_key, art)
     else:
         raise NotFound('Entity')
 
@@ -188,19 +200,18 @@ def cover_art():
         return send_file(cover_path)
 
     im = Image.open(cover_path)
+    mimetype = 'image/{}'.format(im.format.lower())
     if size > im.width and size > im.height:
-        return send_file(cover_path)
+        return send_file(cover_path, mimetype=mimetype)
 
-    size_path = os.path.join(current_app.config['WEBAPP']['cache_dir'], str(size))
-    path = os.path.abspath(os.path.join(size_path, eid))
-    if os.path.exists(path):
-        return send_file(path, mimetype = 'image/' + im.format.lower())
-    if not os.path.exists(size_path):
-        os.makedirs(size_path)
-
-    im.thumbnail([size, size], Image.ANTIALIAS)
-    im.save(path, im.format)
-    return send_file(path, mimetype = 'image/' + im.format.lower())
+    cache_key = "{}-cover-{}".format(eid, size)
+    try:
+        return send_file(cache.get(cache_key), mimetype=mimetype)
+    except CacheMiss:
+        im.thumbnail([size, size], Image.ANTIALIAS)
+        with cache.set_fileobj(cache_key) as fp:
+            im.save(fp, im.format)
+        return send_file(cache.get(cache_key), mimetype=mimetype)
 
 @api.route('/getLyrics.view', methods = [ 'GET', 'POST' ])
 def lyrics():
@@ -227,21 +238,37 @@ def lyrics():
                 value = lyrics
             ))
 
+    # Create a stable, unique, filesystem-compatible identifier for the artist+title
+    unique = hashlib.md5(json.dumps([x.lower() for x in (artist, title)]).encode('utf-8')).hexdigest()
+    cache_key = "lyrics-{}".format(unique)
+
+    lyrics = dict()
     try:
-        r = requests.get("http://api.chartlyrics.com/apiv1.asmx/SearchLyricDirect",
-            params = { 'artist': artist, 'song': title }, timeout = 5)
-        root = ElementTree.fromstring(r.content)
+        lyrics = json.loads(
+            zlib.decompress(
+                current_app.cache.get_value(cache_key)
+            ).decode('utf-8')
+        )
+    except (CacheMiss, zlib.error, TypeError, ValueError):
+        try:
+            r = requests.get("http://api.chartlyrics.com/apiv1.asmx/SearchLyricDirect",
+                             params={'artist': artist, 'song': title}, timeout=5)
+            root = ElementTree.fromstring(r.content)
 
-        ns = { 'cl': 'http://api.chartlyrics.com/' }
-        return request.formatter('lyrics', dict(
-            artist = root.find('cl:LyricArtist', namespaces = ns).text,
-            title = root.find('cl:LyricSong', namespaces = ns).text,
-            value = root.find('cl:Lyric', namespaces = ns).text
-        ))
-    except requests.exceptions.RequestException as e: # pragma: nocover
-        logger.warning('Error while requesting the ChartLyrics API: ' + str(e))
+            ns = {'cl': 'http://api.chartlyrics.com/'}
+            lyrics = dict(
+                artist = root.find('cl:LyricArtist', namespaces=ns).text,
+                title = root.find('cl:LyricSong', namespaces=ns).text,
+                value = root.find('cl:Lyric', namespaces=ns).text
+            )
 
-    return request.formatter('lyrics', dict()) # pragma: nocover
+            current_app.cache.set(
+                cache_key, zlib.compress(json.dumps(lyrics).encode('utf-8'), 9)
+            )
+        except requests.exceptions.RequestException as e: # pragma: nocover
+            logger.warning('Error while requesting the ChartLyrics API: ' + str(e))
+
+    return request.formatter('lyrics', lyrics)
 
 def read_file_as_unicode(path):
     """ Opens a file trying with different encodings and returns the contents as a unicode string """
diff --git a/supysonic/cache.py b/supysonic/cache.py
new file mode 100644
index 0000000..b1b7b35
--- /dev/null
+++ b/supysonic/cache.py
@@ -0,0 +1,231 @@
+# coding: utf-8
+#
+# This file is part of Supysonic.
+# Supysonic is a Python implementation of the Subsonic server API.
+#
+# Copyright (C) 2013-2018 Alban 'spl0k' Féron
+#                    2017 Óscar García Amor
+#
+# Distributed under terms of the GNU AGPLv3 license.
+
+from collections import OrderedDict, namedtuple
+import contextlib
+import errno
+import logging
+import os
+import os.path
+import tempfile
+import threading
+from time import time
+
+from .py23 import scandir, osreplace
+
+
+logger = logging.getLogger(__name__)
+
+
+class CacheMiss(KeyError):
+    """The requested data is not in the cache"""
+    pass
+
+
+class ProtectedError(Exception):
+    """The data cannot be purged from the cache"""
+    pass
+
+
+CacheEntry = namedtuple("CacheEntry", ["size", "expires"])
+NULL_ENTRY = CacheEntry(0, 0)
+
+class Cache(object):
+    """Provides a common interface for caching files to disk"""
+    # Modeled after werkzeug.contrib.cache.FileSystemCache
+
+    # keys must be filename-compatible strings (no paths)
+    # values must be bytes (not strings)
+
+    def __init__(self, cache_dir, max_size, min_time=300, auto_prune=True):
+        """Initialize the cache
+
+        cache_dir: The folder to store cached files
+        max_size: The maximum allowed size of the cache in bytes
+        min_time: The minimum amount of time a file will be stored in the cache
+                  in seconds (default 300 = 5min)
+        auto_prune: If True (default) the cache will automatically be pruned to
+                    the max_size when possible.
+
+        Note that max_size is not a hard restriction and in some cases will
+        temporarily be exceeded, even when auto-pruning is turned on.
+        """
+        self._cache_dir = os.path.abspath(cache_dir)
+        self.min_time = min_time
+        self.max_size = max_size
+        self._auto_prune = auto_prune
+        self._lock = threading.RLock()
+
+        # Create the cache directory
+        try:
+            os.makedirs(self._cache_dir)
+        except OSError as e:
+            if e.errno != errno.EEXIST:
+                raise
+
+        # Make a key -> CacheEntry(size, expiry) map ordered by mtime
+        self._size = 0
+        self._files = OrderedDict()
+        for mtime, size, key in sorted([(f.stat().st_mtime, f.stat().st_size, f.name)
+                                        for f in scandir(self._cache_dir)
+                                        if f.is_file()]):
+            self._files[key] = CacheEntry(size, mtime + self.min_time)
+            self._size += size
+
+    def _filepath(self, key):
+        return os.path.join(self._cache_dir, key)
+
+    def _make_space(self, required_space, key=None):
+        """Delete files to free up the required space (or close to it)
+
+        If key is provided and exists in the cache, its size will be
+        subtracted from the required size.
+        """
+        target = self.max_size - required_space
+        if key is not None:
+            target += self._files.get(key, NULL_ENTRY).size
+
+        with self._lock:
+            # Delete the oldest file until self._size <= target
+            for k in list(self._files.keys()):
+                if self._size <= target:
+                    break
+                try:
+                    self.delete(k)
+                except ProtectedError:
+                    pass
+
+    def _record_file(self, key, size):
+        # If the file is being replaced, add only the difference in size
+        self._size += size - self._files.get(key, NULL_ENTRY).size
+        self._files[key] = CacheEntry(size, int(time()) + self.min_time)
+
+    def _freshen_file(self, key):
+        """Touch the file to change modified time and move it to the end of the cache dict"""
+        old = self._files.pop(key)
+        self._files[key] = CacheEntry(old.size, int(time()) + self.min_time)
+        os.utime(self._filepath(key), None)
+
+    @property
+    def size(self):
+        """The current amount of data cached"""
+        return self._size
+
+    def touch(self, key):
+        """Mark a cache entry as fresh"""
+        with self._lock:
+            if not self.has(key):
+                raise CacheMiss(key)
+            self._freshen_file(key)
+
+    @contextlib.contextmanager
+    def set_fileobj(self, key):
+        """Yields a file object that can have bytes written to it in order to
+        store them in the cache.
+
+        The contents of the file object will be stored in the cache when the
+        context is exited.
+
+        Ex:
+        >>> with cache.set_fileobj(key) as fp:
+        ...     json.dump(some_data, fp)
+        """
+        try:
+            with tempfile.NamedTemporaryFile(dir=self._cache_dir, suffix=".part", delete=True) as f:
+                yield f
+
+                # seek to end and get position to get filesize
+                f.seek(0, 2)
+                size = f.tell()
+
+                with self._lock:
+                    if self._auto_prune:
+                        self._make_space(size, key=key)
+                    osreplace(f.name, self._filepath(key))
+                    self._record_file(key, size)
+        except OSError as e:
+            # Ignore error from trying to delete the renamed temp file
+            if e.errno != errno.ENOENT:
+                raise
+
+    def set(self, key, value):
+        """Set a literal value into the cache and return its path"""
+        with self.set_fileobj(key) as f:
+            f.write(value)
+        return self._filepath(key)
+
+    def set_generated(self, key, gen_function):
+        """Pass the values yielded from the generator function through and set
+        the end result in the cache.
+
+        The contents will be set into the cache only if and when the generator
+        completes.
+
+        Ex:
+        >>> for x in cache.set_generated(key, generator_function):
+        ...     print(x)
+        """
+        with self.set_fileobj(key) as f:
+            for data in gen_function():
+                f.write(data)
+                yield data
+
+    def get(self, key):
+        """Return the path to the file where the cached data is stored"""
+        self.touch(key)
+        return self._filepath(key)
+
+    @contextlib.contextmanager
+    def get_fileobj(self, key):
+        """Yields a file object that can be used to read cached bytes"""
+        with open(self.get(key), 'rb') as f:
+            yield f
+
+    def get_value(self, key):
+        """Return the cached data"""
+        with self.get_fileobj(key) as f:
+            return f.read()
+
+    def delete(self, key):
+        """Delete a file from the cache"""
+        with self._lock:
+            if not self.has(key):
+                return
+            if time() < self._files[key].expires:
+                raise ProtectedError("File has not expired")
+
+            os.remove(self._filepath(key))
+            self._size -= self._files.pop(key).size
+
+    def prune(self):
+        """Prune the cache down to the max size
+
+        Note that protected files are not deleted
+        """
+        self._make_space(0)
+
+    def clear(self):
+        """Clear the cache
+
+        Note that protected files are not deleted
+        """
+        self._make_space(self.max_size)
+
+    def has(self, key):
+        """Check if a key is currently cached"""
+        if key not in self._files:
+            return False
+
+        if not os.path.exists(self._filepath(key)):
+            # Underlying file is gone, remove from the cache
+            self._size -= self._files.pop(key).size
+            return False
+
+        return True
diff --git a/supysonic/config.py b/supysonic/config.py
index f82487c..1501346 100644
--- a/supysonic/config.py
+++ b/supysonic/config.py
@@ -26,6 +26,8 @@ class DefaultConfig(object):
     }
     WEBAPP = {
         'cache_dir': tempdir,
+        'cache_size': 1024,
+        'transcode_cache_size': 512,
         'log_file': None,
         'log_level': 'WARNING',
 
diff --git a/supysonic/py23.py b/supysonic/py23.py
index 319e00e..ae500cd 100644
--- a/supysonic/py23.py
+++ b/supysonic/py23.py
@@ -7,6 +7,31 @@
 #
 # Distributed under terms of the GNU AGPLv3 license.
 
+# Try built-in scandir, fall back to the package for Python 2.7
+try:
+    from os import scandir
+except ImportError:
+    from scandir import scandir
+
+# os.replace was added in Python 3.3, provide a fallback for Python 2.7
+try:
+    from os import replace as osreplace
+except ImportError:
+    # os.rename is equivalent to os.replace except on Windows
+    # On Windows an existing file will not be overwritten
+    # This fallback just attempts to delete the dst file before using rename
+    import sys
+    if sys.platform != 'win32':
+        from os import rename as osreplace
+    else:
+        import os
+        def osreplace(src, dst):
+            try:
+                os.remove(dst)
+            except OSError:
+                pass
+            os.rename(src, dst)
+
 try:
     # Python 2
     strtype = basestring
diff --git a/supysonic/web.py b/supysonic/web.py
index 278e5f8..fc1a906 100644
--- a/supysonic/web.py
+++ b/supysonic/web.py
@@ -17,6 +17,7 @@ from os import makedirs, path, urandom
 from pony.orm import db_session
 
 from .config import IniConfig
+from .cache import Cache
 from .db import init_database
 
 logger = logging.getLogger(__package__)
@@ -53,6 +54,14 @@ def create_application(config = None):
         if extension not in mimetypes.types_map:
             mimetypes.add_type(v, extension, False)
 
+    # Initialize Cache objects
+    # Max size is MB in the config file but Cache expects bytes
+    cache_dir = app.config['WEBAPP']['cache_dir']
+    max_size_cache = app.config['WEBAPP']['cache_size'] * 1024**2
+    max_size_transcodes = app.config['WEBAPP']['transcode_cache_size'] * 1024**2
+    app.cache = Cache(path.join(cache_dir, "cache"), max_size_cache)
+    app.transcode_cache = Cache(path.join(cache_dir, "transcodes"), max_size_transcodes)
+
     # Test for the cache directory
     cache_path = app.config['WEBAPP']['cache_dir']
     if not path.exists(cache_path):
diff --git a/tests/base/__init__.py b/tests/base/__init__.py
index 2f4630e..4343e7b 100644
--- a/tests/base/__init__.py
+++ b/tests/base/__init__.py
@@ -10,6 +10,7 @@
 import unittest
 
 from .test_cli import CLITestCase
+from .test_cache import CacheTestCase
 from .test_config import ConfigTestCase
 from .test_db import DbTestCase
 from .test_lastfm import LastFmTestCase
@@ -20,6 +21,7 @@ from .test_watcher import suite as watcher_suite
 def suite():
     suite = unittest.TestSuite()
 
+    suite.addTest(unittest.makeSuite(CacheTestCase))
     suite.addTest(unittest.makeSuite(ConfigTestCase))
     suite.addTest(unittest.makeSuite(DbTestCase))
     suite.addTest(unittest.makeSuite(ScannerTestCase))
diff --git a/tests/base/test_cache.py b/tests/base/test_cache.py
new file mode 100644
index 0000000..a134b10
--- /dev/null
+++ b/tests/base/test_cache.py
@@ -0,0 +1,278 @@
+#!/usr/bin/env python
+# coding: utf-8
+#
+# This file is part of Supysonic.
+# Supysonic is a Python implementation of the Subsonic server API.
+#
+# Copyright (C) 2018 Alban 'spl0k' Féron
+#
+# Distributed under terms of the GNU AGPLv3 license.
+
+import os
+import unittest
+import shutil
+import time
+import tempfile
+
+from supysonic.cache import Cache, CacheMiss, ProtectedError
+
+
+class CacheTestCase(unittest.TestCase):
+    def setUp(self):
+        self.__dir = tempfile.mkdtemp()
+
+    def tearDown(self):
+        shutil.rmtree(self.__dir)
+
+    def test_existing_files_order(self):
+        cache = Cache(self.__dir, 30)
+        val = b'0123456789'
+        cache.set("key1", val)
+        cache.set("key2", val)
+        cache.set("key3", val)
+        self.assertEqual(cache.size, 30)
+
+        # file mtime is accurate to the second
+        time.sleep(1)
+        cache.get_value("key1")
+
+        cache = Cache(self.__dir, 30, min_time=0)
+        self.assertEqual(cache.size, 30)
+        self.assertTrue(cache.has("key1"))
+        self.assertTrue(cache.has("key2"))
+        self.assertTrue(cache.has("key3"))
+
+        cache.set("key4", val)
+        self.assertEqual(cache.size, 30)
+        self.assertTrue(cache.has("key1"))
+        self.assertFalse(cache.has("key2"))
+        self.assertTrue(cache.has("key3"))
+        self.assertTrue(cache.has("key4"))
+
+    def test_missing(self):
+        cache = Cache(self.__dir, 10)
+        self.assertFalse(cache.has("missing"))
+        with self.assertRaises(CacheMiss):
+            cache.get_value("missing")
+
+    def test_delete_missing(self):
+        cache = Cache(self.__dir, 0, min_time=0)
+        cache.delete("missing1")
+        cache.delete("missing2")
+
+    def test_store_literal(self):
+        cache = Cache(self.__dir, 10)
+        val = b'0123456789'
+        cache.set("key", val)
+        self.assertEqual(cache.size, 10)
+        self.assertTrue(cache.has("key"))
+        self.assertEqual(cache.get_value("key"), val)
+
+    def test_store_generated(self):
+        cache = Cache(self.__dir, 10)
+        val = [b'0', b'12', b'345', b'6789']
+        def gen():
+            for b in val:
+                yield b
+
+        t = []
+        for x in cache.set_generated("key", gen):
+            t.append(x)
+            self.assertEqual(cache.size, 0)
+            self.assertFalse(cache.has("key"))
+
+        self.assertEqual(t, val)
+        self.assertEqual(cache.size, 10)
+        self.assertEqual(cache.get_value("key"), b''.join(val))
+
+    def test_store_to_fp(self):
+        cache = Cache(self.__dir, 10)
+        val = b'0123456789'
+        with cache.set_fileobj("key") as fp:
+            fp.write(val)
+            self.assertEqual(cache.size, 0)
+
+        self.assertEqual(cache.size, 10)
+        self.assertEqual(cache.get_value("key"), val)
+
+    def test_access_data(self):
+        cache = Cache(self.__dir, 25, min_time=0)
+        val = b'0123456789'
+        cache.set("key", val)
+
+        self.assertEqual(cache.get_value("key"), val)
+
+        with cache.get_fileobj("key") as f:
+            self.assertEqual(f.read(), val)
+
+        with open(cache.get("key"), 'rb') as f:
+            self.assertEqual(f.read(), val)
+
+
+    def test_accessing_preserves(self):
+        cache = Cache(self.__dir, 25, min_time=0)
+        val = b'0123456789'
+        cache.set("key1", val)
+        cache.set("key2", val)
+        self.assertEqual(cache.size, 20)
+
+        cache.get_value("key1")
+
+        cache.set("key3", val)
+        self.assertEqual(cache.size, 20)
+        self.assertTrue(cache.has("key1"))
+        self.assertFalse(cache.has("key2"))
+        self.assertTrue(cache.has("key3"))
+
+    def test_automatic_delete_oldest(self):
+        cache = Cache(self.__dir, 25, min_time=0)
+        val = b'0123456789'
+        cache.set("key1", val)
+        self.assertTrue(cache.has("key1"))
+        self.assertEqual(cache.size, 10)
+
+        cache.set("key2", val)
+        self.assertEqual(cache.size, 20)
+        self.assertTrue(cache.has("key1"))
+        self.assertTrue(cache.has("key2"))
+
+        cache.set("key3", val)
+        self.assertEqual(cache.size, 20)
+        self.assertFalse(cache.has("key1"))
+        self.assertTrue(cache.has("key2"))
+        self.assertTrue(cache.has("key3"))
+
+    def test_delete(self):
+        cache = Cache(self.__dir, 25, min_time=0)
+        val = b'0123456789'
+        cache.set("key1", val)
+        self.assertTrue(cache.has("key1"))
+        self.assertEqual(cache.size, 10)
+
+        cache.delete("key1")
+
+        self.assertFalse(cache.has("key1"))
+        self.assertEqual(cache.size, 0)
+
+    def test_cleanup_on_error(self):
+        cache = Cache(self.__dir, 10)
+        def gen():
+            # Cause a TypeError halfway through
+            for b in [b'0', b'12', object(), b'345', b'6789']:
+                yield b
+
+        with self.assertRaises(TypeError):
+            for x in cache.set_generated("key", gen):
+                pass
+
+        # Make sure no partial files are left after the error
+        self.assertEqual(list(os.listdir(self.__dir)), list())
+
+    def test_parallel_generation(self):
+        cache = Cache(self.__dir, 20)
+        def gen():
+            for b in [b'0', b'12', b'345', b'6789']:
+                yield b
+
+        g1 = cache.set_generated("key", gen)
+        g2 = cache.set_generated("key", gen)
+
+        next(g1)
+        files = os.listdir(self.__dir)
+        self.assertEqual(len(files), 1)
+        for x in files:
+            self.assertTrue(x.endswith(".part"))
+
+        next(g2)
+        files = os.listdir(self.__dir)
+        self.assertEqual(len(files), 2)
+        for x in files:
+            self.assertTrue(x.endswith(".part"))
+
+        self.assertEqual(cache.size, 0)
+        for x in g1:
+            pass
+        self.assertEqual(cache.size, 10)
+        self.assertTrue(cache.has("key"))
+
+        # Replace the file - size should stay the same
+        for x in g2:
+            pass
+        self.assertEqual(cache.size, 10)
+        self.assertTrue(cache.has("key"))
+
+        # Only a single file
+        self.assertEqual(len(os.listdir(self.__dir)), 1)
+
+    def test_replace(self):
+        cache = Cache(self.__dir, 20)
+        val_small = b'0'
+        val_big = b'0123456789'
+
+        cache.set("key", val_small)
+        self.assertEqual(cache.size, 1)
+
+        cache.set("key", val_big)
+        self.assertEqual(cache.size, 10)
+
+        cache.set("key", val_small)
+        self.assertEqual(cache.size, 1)
+
+    def test_no_auto_prune(self):
+        cache = Cache(self.__dir, 10, min_time=0, auto_prune=False)
+        val = b'0123456789'
+
+        cache.set("key1", val)
+        cache.set("key2", val)
+        cache.set("key3", val)
+        cache.set("key4", val)
+        self.assertEqual(cache.size, 40)
+        cache.prune()
+
+        self.assertEqual(cache.size, 10)
+
+    def test_min_time_clear(self):
+        cache = Cache(self.__dir, 40, min_time=1)
+        val = b'0123456789'
+
+        cache.set("key1", val)
+        cache.set("key2", val)
+        time.sleep(1)
+        cache.set("key3", val)
+        cache.set("key4", val)
+
+        self.assertEqual(cache.size, 40)
+        cache.clear()
+        self.assertEqual(cache.size, 20)
+        time.sleep(1)
+        cache.clear()
+        self.assertEqual(cache.size, 0)
+
+    def test_not_expired(self):
+        cache = Cache(self.__dir, 40, min_time=1)
+        val = b'0123456789'
+        cache.set("key1", val)
+        with self.assertRaises(ProtectedError):
+            cache.delete("key1")
+        time.sleep(1)
+        cache.delete("key1")
+        self.assertEqual(cache.size, 0)
+
+    def test_missing_cache_file(self):
+        cache = Cache(self.__dir, 10, min_time=0)
+        val = b'0123456789'
+        os.remove(cache.set("key", val))
+
+        self.assertEqual(cache.size, 10)
+        self.assertFalse(cache.has("key"))
+        self.assertEqual(cache.size, 0)
+
+        os.remove(cache.set("key", val))
+        self.assertEqual(cache.size, 10)
+        with self.assertRaises(CacheMiss):
+            cache.get("key")
+        self.assertEqual(cache.size, 0)
+
+
+if __name__ == '__main__':
+    unittest.main()