Decompress needed files while downloading them.

Decompress the files so they can be tracked by AptPackages
and used to generate hashes.

diff --git a/apt_dht/AptPackages.py b/apt_dht/AptPackages.py
index ce462b317bb193298a946c858e6bd380f1434483..a2e743e60fde74f07c9c9bed7d6132b6e66f9d4a 100644 (file)
--- a/apt_dht/AptPackages.py
+++ b/apt_dht/AptPackages.py
@@ -17,6 +17,8 @@ from apt import OpProgress
 
 apt_pkg.init()
 
+TRACKED_FILES = ['release', 'sources', 'packages']
+
 class PackageFileList(DictMixin):
     """Manages a list of package files belonging to a backend.
     
@@ -48,7 +50,7 @@ class PackageFileList(DictMixin):
         fake lists and sources.list.
         """
         filename = cache_path.split('/')[-1]
-        if filename=="Packages" or filename=="Release" or filename=="Sources":
+        if filename.lower() in TRACKED_FILES:
             log.msg("Registering package file: "+cache_path)
             self.packages[cache_path] = file_path
             return True

diff --git a/apt_dht/MirrorManager.py b/apt_dht/MirrorManager.py
index e5b8b1ccddf13217e2c4cf5635b24d46df4140b0..efa46d8d4529302d7c3400ee74221bb407bf5ec6 100644 (file)
--- a/apt_dht/MirrorManager.py
+++ b/apt_dht/MirrorManager.py
@@ -1,4 +1,7 @@
 
+from bz2 import BZ2Decompressor
+from zlib import decompressobj, MAX_WBITS
+from gzip import FCOMMENT, FEXTRA, FHCRC, FNAME, FTEXT
 from urlparse import urlparse
 import os
 
@@ -12,22 +15,39 @@ from AptPackages import AptPackages
 
 aptpkg_dir='.apt-dht'
 
+DECOMPRESS_EXTS = ['.gz', '.bz2']
+DECOMPRESS_FILES = ['release', 'sources', 'packages']
+
 class MirrorError(Exception):
     """Exception raised when there's a problem with the mirror."""
 
 class ProxyFileStream(stream.SimpleStream):
     """Saves a stream to a file while providing a new stream."""
     
-    def __init__(self, stream, outFile):
+    def __init__(self, stream, outFile, decompress = None, decFile = None):
         """Initializes the proxy.
         
         @type stream: C{twisted.web2.stream.IByteStream}
         @param stream: the input stream to read from
         @type outFile: C{twisted.python.filepath.FilePath}
         @param outFile: the file to write to
+        @type decompress: C{string}
+        @param decompress: also decompress the file as this type
+            (currently only '.gz' and '.bz2' are supported)
+        @type decFile: C{twisted.python.filepath.FilePath}
+        @param decFile: the file to write the decompressed data to
         """
         self.stream = stream
         self.outFile = outFile.open('w')
+        self.gzfile = None
+        self.bz2file = None
+        if decompress == ".gz":
+            self.gzheader = True
+            self.gzfile = decFile.open('w')
+            self.gzdec = decompressobj(-MAX_WBITS)
+        elif decompress == ".bz2":
+            self.bz2file = decFile.open('w')
+            self.bz2dec = BZ2Decompressor()
         self.length = self.stream.length
         self.start = 0
         self.doneDefer = defer.Deferred()
@@ -36,6 +56,15 @@ class ProxyFileStream(stream.SimpleStream):
         """Close the output file."""
         if not self.outFile.closed:
             self.outFile.close()
+            if self.gzfile:
+                data_dec = self.gzdec.flush()
+                self.gzfile.write(data_dec)
+                self.gzfile.close()
+                self.gzfile = None
+            if self.bz2file:
+                self.bz2file.close()
+                self.bz2file = None
+                
             self.doneDefer.callback(1)
     
     def read(self):
@@ -58,8 +87,53 @@ class ProxyFileStream(stream.SimpleStream):
             return data
         
         self.outFile.write(data)
+        if self.gzfile:
+            if self.gzheader:
+                self.gzheader = False
+                new_data = self._remove_gzip_header(data)
+                dec_data = self.gzdec.decompress(new_data)
+            else:
+                dec_data = self.gzdec.decompress(data)
+            self.gzfile.write(dec_data)
+        if self.bz2file:
+            dec_data = self.bz2dec.decompress(data)
+            self.bz2file.write(dec_data)
         return data
     
+    def _remove_gzip_header(self, data):
+        if data[:2] != '\037\213':
+            raise IOError, 'Not a gzipped file'
+        if ord(data[2]) != 8:
+            raise IOError, 'Unknown compression method'
+        flag = ord(data[3])
+        # modtime = self.fileobj.read(4)
+        # extraflag = self.fileobj.read(1)
+        # os = self.fileobj.read(1)
+
+        skip = 10
+        if flag & FEXTRA:
+            # Read & discard the extra field, if present
+            xlen = ord(data[10])
+            xlen = xlen + 256*ord(data[11])
+            skip = skip + 2 + xlen
+        if flag & FNAME:
+            # Read and discard a null-terminated string containing the filename
+            while True:
+                if not data[skip] or data[skip] == '\000':
+                    break
+                skip += 1
+            skip += 1
+        if flag & FCOMMENT:
+            # Read and discard a null-terminated string containing a comment
+            while True:
+                if not data[skip] or data[skip] == '\000':
+                    break
+                skip += 1
+            skip += 1
+        if flag & FHCRC:
+            skip += 2     # Read & discard the 16-bit header CRC
+        return data[skip:]
+
     def close(self):
         """Clean everything up and return None to future reads."""
         self.length = 0
@@ -112,11 +186,6 @@ class MirrorManager:
             site_cache = os.path.join(self.cache_dir, aptpkg_dir, 'mirrors', site + baseDir.replace('/', '_'))
             self.apt_caches[site][baseDir] = AptPackages(site_cache)
     
-    def updatedFile(self, url, file_path):
-        site, baseDir, path = self.extractPath(url)
-        self.init(site, baseDir)
-        self.apt_caches[site][baseDir].file_updated(path, file_path)
-    
     def findHash(self, url):
         site, baseDir, path = self.extractPath(url)
         if site in self.apt_caches and baseDir in self.apt_caches[site]:
@@ -138,22 +207,39 @@ class MirrorManager:
             destFile.remove()
         else:
             destFile.parent().makedirs()
+            
+        root, ext = os.path.splitext(destFile.basename())
+        if root.lower() in DECOMPRESS_FILES and ext.lower() in DECOMPRESS_EXTS:
+            ext = ext.lower()
+            decFile = destFile.sibling(root)
+            log.msg('Decompressing to: %s' % decFile.path)
+            if decFile.exists():
+                log.msg('File already exists, removing: %s' % decFile.path)
+                decFile.remove()
+        else:
+            ext = None
+            decFile = None
         
         orig_stream = response.stream
-        response.stream = ProxyFileStream(orig_stream, destFile)
+        response.stream = ProxyFileStream(orig_stream, destFile, ext, decFile)
         response.stream.doneDefer.addCallback(self.save_complete, url, destFile,
-                                              response.headers.getHeader('Last-Modified'))
+                                              response.headers.getHeader('Last-Modified'),
+                                              ext, decFile)
         response.stream.doneDefer.addErrback(self.save_error, url)
         return response
 
-    def save_complete(self, result, url, destFile, modtime = None):
+    def save_complete(self, result, url, destFile, modtime = None, ext = None, decFile = None):
         """Update the modification time and AptPackages."""
         if modtime:
             os.utime(destFile.path, (modtime, modtime))
+            if ext:
+                os.utime(decFile.path, (modtime, modtime))
             
         site, baseDir, path = self.extractPath(url)
         self.init(site, baseDir)
         self.apt_caches[site][baseDir].file_updated(path, destFile.path)
+        if ext:
+            self.apt_caches[site][baseDir].file_updated(path[:-len(ext)], decFile.path)
 
     def save_error(self, failure, url):
         """An error has occurred in downloadign or saving the file."""