bitbake: copy bb.fetch to bb.fetch2 as initial code base for fetcher overhaul

Signed-off-by: Yu Ke <ke.yu@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 836 insertions, 0 deletions

diff --git a/lib/bb/fetch2/__init__.py b/lib/bb/fetch2/__init__.py
new file mode 100644
index 000000000..f7153ebce
--- /dev/null
+++ b/lib/bb/fetch2/__init__.py
@@ -0,0 +1,836 @@
+# ex:ts=4:sw=4:sts=4:et
+# -*- tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*-
+"""
+BitBake 'Fetch' implementations
+
+Classes for obtaining upstream sources for the
+BitBake build tools.
+"""
+
+# Copyright (C) 2003, 2004  Chris Larson
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+# Based on functions from the base bb module, Copyright 2003 Holger Schurig
+
+from __future__ import absolute_import
+from __future__ import print_function
+import os, re
+import logging
+import bb
+from   bb import data
+from   bb import persist_data
+
+logger = logging.getLogger("BitBake.Fetch")
+
+class MalformedUrl(Exception):
+    """Exception raised when encountering an invalid url"""
+
+class FetchError(Exception):
+    """Exception raised when a download fails"""
+
+class NoMethodError(Exception):
+    """Exception raised when there is no method to obtain a supplied url or set of urls"""
+
+class MissingParameterError(Exception):
+    """Exception raised when a fetch method is missing a critical parameter in the url"""
+
+class ParameterError(Exception):
+    """Exception raised when a url cannot be proccessed due to invalid parameters."""
+
+class MD5SumError(Exception):
+    """Exception raised when a MD5SUM of a file does not match the expected one"""
+
+class InvalidSRCREV(Exception):
+    """Exception raised when an invalid SRCREV is encountered"""
+
+def decodeurl(url):
+    """Decodes an URL into the tokens (scheme, network location, path,
+    user, password, parameters).
+    """
+
+    m = re.compile('(?P<type>[^:]*)://((?P<user>.+)@)?(?P<location>[^;]+)(;(?P<parm>.*))?').match(url)
+    if not m:
+        raise MalformedUrl(url)
+
+    type = m.group('type')
+    location = m.group('location')
+    if not location:
+        raise MalformedUrl(url)
+    user = m.group('user')
+    parm = m.group('parm')
+
+    locidx = location.find('/')
+    if locidx != -1 and type.lower() != 'file':
+        host = location[:locidx]
+        path = location[locidx:]
+    else:
+        host = ""
+        path = location
+    if user:
+        m = re.compile('(?P<user>[^:]+)(:?(?P<pswd>.*))').match(user)
+        if m:
+            user = m.group('user')
+            pswd = m.group('pswd')
+    else:
+        user = ''
+        pswd = ''
+
+    p = {}
+    if parm:
+        for s in parm.split(';'):
+            s1, s2 = s.split('=')
+            p[s1] = s2
+
+    return (type, host, path, user, pswd, p)
+
+def encodeurl(decoded):
+    """Encodes a URL from tokens (scheme, network location, path,
+    user, password, parameters).
+    """
+
+    (type, host, path, user, pswd, p) = decoded
+
+    if not type or not path:
+        raise MissingParameterError("Type or path url components missing when encoding %s" % decoded)
+    url = '%s://' % type
+    if user:
+        url += "%s" % user
+        if pswd:
+            url += ":%s" % pswd
+        url += "@"
+    if host:
+        url += "%s" % host
+    url += "%s" % path
+    if p:
+        for parm in p:
+            url += ";%s=%s" % (parm, p[parm])
+
+    return url
+
+def uri_replace(uri, uri_find, uri_replace, d):
+    if not uri or not uri_find or not uri_replace:
+        logger.debug(1, "uri_replace: passed an undefined value, not replacing")
+    uri_decoded = list(decodeurl(uri))
+    uri_find_decoded = list(decodeurl(uri_find))
+    uri_replace_decoded = list(decodeurl(uri_replace))
+    result_decoded = ['', '', '', '', '', {}]
+    for i in uri_find_decoded:
+        loc = uri_find_decoded.index(i)
+        result_decoded[loc] = uri_decoded[loc]
+        if isinstance(i, basestring):
+            if (re.match(i, uri_decoded[loc])):
+                result_decoded[loc] = re.sub(i, uri_replace_decoded[loc], uri_decoded[loc])
+                if uri_find_decoded.index(i) == 2:
+                    if d:
+                        localfn = bb.fetch.localpath(uri, d)
+                        if localfn:
+                            result_decoded[loc] = os.path.join(os.path.dirname(result_decoded[loc]), os.path.basename(bb.fetch.localpath(uri, d)))
+            else:
+                return uri
+    return encodeurl(result_decoded)
+
+methods = []
+urldata_cache = {}
+saved_headrevs = {}
+
+def fetcher_init(d):
+    """
+    Called to initialize the fetchers once the configuration data is known.
+    Calls before this must not hit the cache.
+    """
+    pd = persist_data.persist(d)
+    # When to drop SCM head revisions controlled by user policy
+    srcrev_policy = bb.data.getVar('BB_SRCREV_POLICY', d, 1) or "clear"
+    if srcrev_policy == "cache":
+        logger.debug(1, "Keeping SRCREV cache due to cache policy of: %s", srcrev_policy)
+    elif srcrev_policy == "clear":
+        logger.debug(1, "Clearing SRCREV cache due to cache policy of: %s", srcrev_policy)
+        try:
+            bb.fetch.saved_headrevs = pd['BB_URI_HEADREVS'].items()
+        except:
+            pass
+        del pd['BB_URI_HEADREVS']
+    else:
+        raise FetchError("Invalid SRCREV cache policy of: %s" % srcrev_policy)
+
+    for m in methods:
+        if hasattr(m, "init"):
+            m.init(d)
+
+def fetcher_compare_revisions(d):
+    """
+    Compare the revisions in the persistant cache with current values and
+    return true/false on whether they've changed.
+    """
+
+    pd = persist_data.persist(d)
+    data = pd['BB_URI_HEADREVS'].items()
+    data2 = bb.fetch.saved_headrevs
+
+    changed = False
+    for key in data:
+        if key not in data2 or data2[key] != data[key]:
+            logger.debug(1, "%s changed", key)
+            changed = True
+            return True
+        else:
+            logger.debug(2, "%s did not change", key)
+    return False
+
+# Function call order is usually:
+#   1. init
+#   2. go
+#   3. localpaths
+# localpath can be called at any time
+
+def init(urls, d, setup = True):
+    urldata = {}
+
+    fn = bb.data.getVar('FILE', d, 1)
+    if fn in urldata_cache:
+        urldata = urldata_cache[fn]
+
+    for url in urls:
+        if url not in urldata:
+            urldata[url] = FetchData(url, d)
+
+    if setup:
+        for url in urldata:
+            if not urldata[url].setup:
+                urldata[url].setup_localpath(d)
+
+    urldata_cache[fn] = urldata
+    return urldata
+
+def mirror_from_string(data):
+    return [ i.split() for i in (data or "").replace('\\n','\n').split('\n') if i ]
+
+def removefile(f):
+    try:
+        os.remove(f)
+    except:
+        pass
+
+def verify_checksum(u, ud, d):
+    """
+    verify the MD5 and SHA256 checksum for downloaded src
+
+    return value:
+        - True: checksum matched
+        - False: checksum unmatched
+
+    if checksum is missing in recipes file, "BB_STRICT_CHECKSUM" decide the return value.
+    if BB_STRICT_CHECKSUM = "1" then return false as unmatched, otherwise return true as
+    matched
+    """
+
+    if not ud.type in ["http", "https", "ftp", "ftps"]:
+        return
+
+    md5data = bb.utils.md5_file(ud.localpath)
+    sha256data = bb.utils.sha256_file(ud.localpath)
+
+    if (ud.md5_expected == None or ud.sha256_expected == None):
+        logger.warn('Missing SRC_URI checksum for %s, consider adding to the recipe:\n'
+                    'SRC_URI[%s] = "%s"\nSRC_URI[%s] = "%s"',
+                    ud.localpath, ud.md5_name, md5data,
+                    ud.sha256_name, sha256data)
+        if bb.data.getVar("BB_STRICT_CHECKSUM", d, True) == "1":
+            raise FetchError("No checksum specified for %s." % u)
+        return
+
+    if (ud.md5_expected != md5data or ud.sha256_expected != sha256data):
+        logger.error('The checksums for "%s" did not match.\n'
+                     '  MD5: expected "%s", got "%s"\n'
+                     '  SHA256: expected "%s", got "%s"\n',
+                     ud.localpath, ud.md5_expected, md5data,
+                     ud.sha256_expected, sha256data)
+        raise FetchError("%s checksum mismatch." % u)
+
+def go(d, urls = None):
+    """
+    Fetch all urls
+    init must have previously been called
+    """
+    if not urls:
+        urls = d.getVar("SRC_URI", 1).split()
+    urldata = init(urls, d, True)
+
+    for u in urls:
+        ud = urldata[u]
+        m = ud.method
+        localpath = ""
+
+        if not ud.localfile:
+            continue
+
+        lf = bb.utils.lockfile(ud.lockfile)
+
+        if m.try_premirror(u, ud, d):
+            # First try fetching uri, u, from PREMIRRORS
+            mirrors = mirror_from_string(bb.data.getVar('PREMIRRORS', d, True))
+            localpath = try_mirrors(d, u, mirrors, False, m.forcefetch(u, ud, d))
+        elif os.path.exists(ud.localfile):
+            localpath = ud.localfile
+
+        # Need to re-test forcefetch() which will return true if our copy is too old
+        if m.forcefetch(u, ud, d) or not localpath:
+            # Next try fetching from the original uri, u
+            try:
+                m.go(u, ud, d)
+                localpath = ud.localpath
+            except FetchError:
+                # Remove any incomplete file
+                removefile(ud.localpath)
+                # Finally, try fetching uri, u, from MIRRORS
+                mirrors = mirror_from_string(bb.data.getVar('MIRRORS', d, True))
+                localpath = try_mirrors (d, u, mirrors)
+                if not localpath or not os.path.exists(localpath):
+                    raise FetchError("Unable to fetch URL %s from any source." % u)
+
+        ud.localpath = localpath
+
+        if os.path.exists(ud.md5):
+            # Touch the md5 file to show active use of the download
+            try:
+                os.utime(ud.md5, None)
+            except:
+                # Errors aren't fatal here
+                pass
+        else:
+            # Only check the checksums if we've not seen this item before
+            verify_checksum(u, ud, d)
+            Fetch.write_md5sum(u, ud, d)
+
+        bb.utils.unlockfile(lf)
+
+def checkstatus(d, urls = None):
+    """
+    Check all urls exist upstream
+    init must have previously been called
+    """
+    urldata = init([], d, True)
+
+    if not urls:
+        urls = urldata
+
+    for u in urls:
+        ud = urldata[u]
+        m = ud.method
+        logger.debug(1, "Testing URL %s", u)
+        # First try checking uri, u, from PREMIRRORS
+        mirrors = mirror_from_string(bb.data.getVar('PREMIRRORS', d, True))
+        ret = try_mirrors(d, u, mirrors, True)
+        if not ret:
+            # Next try checking from the original uri, u
+            try:
+                ret = m.checkstatus(u, ud, d)
+            except:
+                # Finally, try checking uri, u, from MIRRORS
+                mirrors = mirror_from_string(bb.data.getVar('MIRRORS', d, True))
+                ret = try_mirrors (d, u, mirrors, True)
+
+        if not ret:
+            raise FetchError("URL %s doesn't work" % u)
+
+def localpaths(d):
+    """
+    Return a list of the local filenames, assuming successful fetch
+    """
+    local = []
+    urldata = init([], d, True)
+
+    for u in urldata:
+        ud = urldata[u]
+        local.append(ud.localpath)
+
+    return local
+
+srcrev_internal_call = False
+
+def get_srcrev(d):
+    """
+    Return the version string for the current package
+    (usually to be used as PV)
+    Most packages usually only have one SCM so we just pass on the call.
+    In the multi SCM case, we build a value based on SRCREV_FORMAT which must
+    have been set.
+    """
+
+    #
+    # Ugly code alert. localpath in the fetchers will try to evaluate SRCREV which
+    # could translate into a call to here. If it does, we need to catch this
+    # and provide some way so it knows get_srcrev is active instead of being
+    # some number etc. hence the srcrev_internal_call tracking and the magic
+    # "SRCREVINACTION" return value.
+    #
+    # Neater solutions welcome!
+    #
+    if bb.fetch.srcrev_internal_call:
+        return "SRCREVINACTION"
+
+    scms = []
+
+    # Only call setup_localpath on URIs which supports_srcrev()
+    urldata = init(bb.data.getVar('SRC_URI', d, 1).split(), d, False)
+    for u in urldata:
+        ud = urldata[u]
+        if ud.method.supports_srcrev():
+            if not ud.setup:
+                ud.setup_localpath(d)
+            scms.append(u)
+
+    if len(scms) == 0:
+        logger.error("SRCREV was used yet no valid SCM was found in SRC_URI")
+        raise ParameterError
+
+    if bb.data.getVar('BB_SRCREV_POLICY', d, True) != "cache":
+        bb.data.setVar('__BB_DONT_CACHE', '1', d)
+
+    if len(scms) == 1:
+        return urldata[scms[0]].method.sortable_revision(scms[0], urldata[scms[0]], d)
+
+    #
+    # Mutiple SCMs are in SRC_URI so we resort to SRCREV_FORMAT
+    #
+    format = bb.data.getVar('SRCREV_FORMAT', d, 1)
+    if not format:
+        logger.error("The SRCREV_FORMAT variable must be set when multiple SCMs are used.")
+        raise ParameterError
+
+    for scm in scms:
+        if 'name' in urldata[scm].parm:
+            name = urldata[scm].parm["name"]
+            rev = urldata[scm].method.sortable_revision(scm, urldata[scm], d)
+            format = format.replace(name, rev)
+
+    return format
+
+def localpath(url, d, cache = True):
+    """
+    Called from the parser with cache=False since the cache isn't ready
+    at this point. Also called from classed in OE e.g. patch.bbclass
+    """
+    ud = init([url], d)
+    if ud[url].method:
+        return ud[url].localpath
+    return url
+
+def runfetchcmd(cmd, d, quiet = False):
+    """
+    Run cmd returning the command output
+    Raise an error if interrupted or cmd fails
+    Optionally echo command output to stdout
+    """
+
+    # Need to export PATH as binary could be in metadata paths
+    # rather than host provided
+    # Also include some other variables.
+    # FIXME: Should really include all export varaiables?
+    exportvars = ['PATH', 'GIT_PROXY_COMMAND', 'GIT_PROXY_HOST',
+                  'GIT_PROXY_PORT', 'GIT_CONFIG', 'http_proxy', 'ftp_proxy',
+                  'https_proxy', 'no_proxy', 'ALL_PROXY', 'all_proxy',
+                  'SSH_AUTH_SOCK', 'SSH_AGENT_PID', 'HOME']
+
+    for var in exportvars:
+        val = data.getVar(var, d, True)
+        if val:
+            cmd = 'export ' + var + '=\"%s\"; %s' % (val, cmd)
+
+    logger.debug(1, "Running %s", cmd)
+
+    # redirect stderr to stdout
+    stdout_handle = os.popen(cmd + " 2>&1", "r")
+    output = ""
+
+    while True:
+        line = stdout_handle.readline()
+        if not line:
+            break
+        if not quiet:
+            print(line, end=' ')
+        output += line
+
+    status = stdout_handle.close() or 0
+    signal = status >> 8
+    exitstatus = status & 0xff
+
+    if signal:
+        raise FetchError("Fetch command %s failed with signal %s, output:\n%s" % (cmd, signal, output))
+    elif status != 0:
+        raise FetchError("Fetch command %s failed with exit code %s, output:\n%s" % (cmd, status, output))
+
+    return output
+
+def try_mirrors(d, uri, mirrors, check = False, force = False):
+    """
+    Try to use a mirrored version of the sources.
+    This method will be automatically called before the fetchers go.
+
+    d Is a bb.data instance
+    uri is the original uri we're trying to download
+    mirrors is the list of mirrors we're going to try
+    """
+    fpath = os.path.join(data.getVar("DL_DIR", d, 1), os.path.basename(uri))
+    if not check and os.access(fpath, os.R_OK) and not force:
+        logger.debug(1, "%s already exists, skipping checkout.", fpath)
+        return fpath
+
+    ld = d.createCopy()
+    for (find, replace) in mirrors:
+        newuri = uri_replace(uri, find, replace, ld)
+        if newuri != uri:
+            try:
+                ud = FetchData(newuri, ld)
+            except bb.fetch.NoMethodError:
+                logger.debug(1, "No method for %s", uri)
+                continue
+
+            ud.setup_localpath(ld)
+
+            try:
+                if check:
+                    found = ud.method.checkstatus(newuri, ud, ld)
+                    if found:
+                        return found
+                else:
+                    ud.method.go(newuri, ud, ld)
+                    return ud.localpath
+            except (bb.fetch.MissingParameterError,
+                    bb.fetch.FetchError,
+                    bb.fetch.MD5SumError):
+                import sys
+                (type, value, traceback) = sys.exc_info()
+                logger.debug(2, "Mirror fetch failure: %s", value)
+                removefile(ud.localpath)
+                continue
+    return None
+
+
+class FetchData(object):
+    """
+    A class which represents the fetcher state for a given URI.
+    """
+    def __init__(self, url, d):
+        self.localfile = ""
+        (self.type, self.host, self.path, self.user, self.pswd, self.parm) = decodeurl(data.expand(url, d))
+        self.date = Fetch.getSRCDate(self, d)
+        self.url = url
+        if not self.user and "user" in self.parm:
+            self.user = self.parm["user"]
+        if not self.pswd and "pswd" in self.parm:
+            self.pswd = self.parm["pswd"]
+        self.setup = False
+
+        if "name" in self.parm:
+            self.md5_name = "%s.md5sum" % self.parm["name"]
+            self.sha256_name = "%s.sha256sum" % self.parm["name"]
+        else:
+            self.md5_name = "md5sum"
+            self.sha256_name = "sha256sum"
+        self.md5_expected = bb.data.getVarFlag("SRC_URI", self.md5_name, d)
+        self.sha256_expected = bb.data.getVarFlag("SRC_URI", self.sha256_name, d)
+
+        for m in methods:
+            if m.supports(url, self, d):
+                self.method = m
+                return
+        raise NoMethodError("Missing implementation for url %s" % url)
+
+    def setup_localpath(self, d):
+        self.setup = True
+        if "localpath" in self.parm:
+            # if user sets localpath for file, use it instead.
+            self.localpath = self.parm["localpath"]
+            self.basename = os.path.basename(self.localpath)
+        else:
+            premirrors = bb.data.getVar('PREMIRRORS', d, True)
+            local = ""
+            if premirrors and self.url:
+                aurl = self.url.split(";")[0]
+                mirrors = mirror_from_string(premirrors)
+                for (find, replace) in mirrors:
+                    if replace.startswith("file://"):
+                        path = aurl.split("://")[1]
+                        path = path.split(";")[0]
+                        local = replace.split("://")[1] + os.path.basename(path)
+                        if local == aurl or not os.path.exists(local) or os.path.isdir(local):
+                            local = ""
+                self.localpath = local
+            if not local:
+                try:
+                    bb.fetch.srcrev_internal_call = True
+                    self.localpath = self.method.localpath(self.url, self, d)
+                finally:
+                    bb.fetch.srcrev_internal_call = False
+                # We have to clear data's internal caches since the cached value of SRCREV is now wrong.
+                # Horrible...
+                bb.data.delVar("ISHOULDNEVEREXIST", d)
+
+        if self.localpath is not None:
+            # Note: These files should always be in DL_DIR whereas localpath may not be.
+            basepath = bb.data.expand("${DL_DIR}/%s" % os.path.basename(self.localpath), d)
+            self.md5 = basepath + '.md5'
+            self.lockfile = basepath + '.lock'
+
+
+class Fetch(object):
+    """Base class for 'fetch'ing data"""
+
+    def __init__(self, urls = []):
+        self.urls = []
+
+    def supports(self, url, urldata, d):
+        """
+        Check to see if this fetch class supports a given url.
+        """
+        return 0
+
+    def localpath(self, url, urldata, d):
+        """
+        Return the local filename of a given url assuming a successful fetch.
+        Can also setup variables in urldata for use in go (saving code duplication
+        and duplicate code execution)
+        """
+        return url
+    def _strip_leading_slashes(self, relpath):
+        """
+        Remove leading slash as os.path.join can't cope
+        """
+        while os.path.isabs(relpath):
+            relpath = relpath[1:]
+        return relpath
+
+    def setUrls(self, urls):
+        self.__urls = urls
+
+    def getUrls(self):
+        return self.__urls
+
+    urls = property(getUrls, setUrls, None, "Urls property")
+
+    def forcefetch(self, url, urldata, d):
+        """
+        Force a fetch, even if localpath exists?
+        """
+        return False
+
+    def supports_srcrev(self):
+        """
+        The fetcher supports auto source revisions (SRCREV)
+        """
+        return False
+
+    def go(self, url, urldata, d):
+        """
+        Fetch urls
+        Assumes localpath was called first
+        """
+        raise NoMethodError("Missing implementation for url")
+
+    def try_premirror(self, url, urldata, d):
+        """
+        Should premirrors be used?
+        """
+        if urldata.method.forcefetch(url, urldata, d):
+            return True
+        elif os.path.exists(urldata.md5) and os.path.exists(urldata.localfile):
+            return False
+        else:
+            return True
+
+    def checkstatus(self, url, urldata, d):
+        """
+        Check the status of a URL
+        Assumes localpath was called first
+        """
+        logger.info("URL %s could not be checked for status since no method exists.", url)
+        return True
+
+    def getSRCDate(urldata, d):
+        """
+        Return the SRC Date for the component
+
+        d the bb.data module
+        """
+        if "srcdate" in urldata.parm:
+            return urldata.parm['srcdate']
+
+        pn = data.getVar("PN", d, 1)
+
+        if pn:
+            return data.getVar("SRCDATE_%s" % pn, d, 1) or data.getVar("CVSDATE_%s" % pn, d, 1) or data.getVar("SRCDATE", d, 1) or data.getVar("CVSDATE", d, 1) or data.getVar("DATE", d, 1)
+
+        return data.getVar("SRCDATE", d, 1) or data.getVar("CVSDATE", d, 1) or data.getVar("DATE", d, 1)
+    getSRCDate = staticmethod(getSRCDate)
+
+    def srcrev_internal_helper(ud, d):
+        """
+        Return:
+            a) a source revision if specified
+            b) True if auto srcrev is in action
+            c) False otherwise
+        """
+
+        if 'rev' in ud.parm:
+            return ud.parm['rev']
+
+        if 'tag' in ud.parm:
+            return ud.parm['tag']
+
+        rev = None
+        if 'name' in ud.parm:
+            pn = data.getVar("PN", d, 1)
+            rev = data.getVar("SRCREV_%s_pn-%s" % (ud.parm['name'], pn), d, 1)
+            if not rev:
+                rev = data.getVar("SRCREV_pn-%s_%s" % (pn, ud.parm['name']), d, 1)
+            if not rev:
+                rev = data.getVar("SRCREV_%s" % (ud.parm['name']), d, 1)
+        if not rev:
+            rev = data.getVar("SRCREV", d, 1)
+        if rev == "INVALID":
+            raise InvalidSRCREV("Please set SRCREV to a valid value")
+        if not rev:
+            return False
+        if rev is "SRCREVINACTION":
+            return True
+        return rev
+
+    srcrev_internal_helper = staticmethod(srcrev_internal_helper)
+
+    def localcount_internal_helper(ud, d):
+        """
+        Return:
+            a) a locked localcount if specified
+            b) None otherwise
+        """
+
+        localcount = None
+        if 'name' in ud.parm:
+            pn = data.getVar("PN", d, 1)
+            localcount = data.getVar("LOCALCOUNT_" + ud.parm['name'], d, 1)
+        if not localcount:
+            localcount = data.getVar("LOCALCOUNT", d, 1)
+        return localcount
+
+    localcount_internal_helper = staticmethod(localcount_internal_helper)
+
+    def verify_md5sum(ud, got_sum):
+        """
+        Verify the md5sum we wanted with the one we got
+        """
+        wanted_sum = ud.parm.get('md5sum')
+        if not wanted_sum:
+            return True
+
+        return wanted_sum == got_sum
+    verify_md5sum = staticmethod(verify_md5sum)
+
+    def write_md5sum(url, ud, d):
+        md5data = bb.utils.md5_file(ud.localpath)
+        # verify the md5sum
+        if not Fetch.verify_md5sum(ud, md5data):
+            raise MD5SumError(url)
+
+        md5out = file(ud.md5, 'w')
+        md5out.write(md5data)
+        md5out.close()
+    write_md5sum = staticmethod(write_md5sum)
+
+    def latest_revision(self, url, ud, d):
+        """
+        Look in the cache for the latest revision, if not present ask the SCM.
+        """
+        if not hasattr(self, "_latest_revision"):
+            raise ParameterError
+
+        pd = persist_data.persist(d)
+        revs = pd['BB_URI_HEADREVS']
+        key = self.generate_revision_key(url, ud, d)
+        rev = revs[key]
+        if rev != None:
+            return str(rev)
+
+        revs[key] = rev = self._latest_revision(url, ud, d)
+        return rev
+
+    def sortable_revision(self, url, ud, d):
+        """
+
+        """
+        if hasattr(self, "_sortable_revision"):
+            return self._sortable_revision(url, ud, d)
+
+        pd = persist_data.persist(d)
+        localcounts = pd['BB_URI_LOCALCOUNT']
+        key = self.generate_revision_key(url, ud, d)
+
+        latest_rev = self._build_revision(url, ud, d)
+        last_rev = localcounts[key + '_rev']
+        uselocalcount = bb.data.getVar("BB_LOCALCOUNT_OVERRIDE", d, True) or False
+        count = None
+        if uselocalcount:
+            count = Fetch.localcount_internal_helper(ud, d)
+        if count is None:
+            count = localcounts[key + '_count']
+
+        if last_rev == latest_rev:
+            return str(count + "+" + latest_rev)
+
+        buildindex_provided = hasattr(self, "_sortable_buildindex")
+        if buildindex_provided:
+            count = self._sortable_buildindex(url, ud, d, latest_rev)
+
+        if count is None:
+            count = "0"
+        elif uselocalcount or buildindex_provided:
+            count = str(count)
+        else:
+            count = str(int(count) + 1)
+
+        localcounts[key + '_rev'] = latest_rev
+        localcounts[key + '_count'] = count
+
+        return str(count + "+" + latest_rev)
+
+    def generate_revision_key(self, url, ud, d):
+        key = self._revision_key(url, ud, d)
+        return "%s-%s" % (key, bb.data.getVar("PN", d, True) or "")
+
+from . import cvs
+from . import git
+from . import local
+from . import svn
+from . import wget
+from . import svk
+from . import ssh
+from . import perforce
+from . import bzr
+from . import hg
+from . import osc
+from . import repo
+
+methods.append(local.Local())
+methods.append(wget.Wget())
+methods.append(svn.Svn())
+methods.append(git.Git())
+methods.append(cvs.Cvs())
+methods.append(svk.Svk())
+methods.append(ssh.SSH())
+methods.append(perforce.Perforce())
+methods.append(bzr.Bzr())
+methods.append(hg.Hg())
+methods.append(osc.Osc())
+methods.append(repo.Repo())