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CherryPy / cherrypy / _cpengine.py

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Robert Brewer 8865db7 





















Robert Brewer 3cfe780 
Robert Brewer 8865db7 























































































Robert Brewer 5640ee0 
Robert Brewer 8865db7 
Robert Brewer 5640ee0 
Robert Brewer 8865db7 








Robert Brewer a1daa20 
Robert Brewer 8865db7 
































































Robert Brewer 3cfe780 
Robert Brewer 8865db7 
"""Create and manage the CherryPy application server engine."""

import cgi
import sys
import threading
import time
import warnings

import cherrypy
from cherrypy import _cphttptools, filters
from cherrypy.lib import autoreload, profiler, cptools

# Use a flag to indicate the state of the application server.
STOPPED = 0
STARTING = None
STARTED = 1


class Engine(object):
    """The application server engine, connecting HTTP servers to Requests."""
    
    request_class = _cphttptools.Request
    response_class = _cphttptools.Response
    
    def __init__(self):
        self.state = STOPPED
        
        self.seen_threads = {}
        self.interrupt = None
        
        # Startup/shutdown hooks
        self.on_start_server_list = []
        self.on_stop_server_list = []
        self.on_start_thread_list = []
        self.on_stop_thread_list = []
    
    def setup(self):
        # The only reason this method isn't in __init__ is so that
        # "import cherrypy" can create an Engine() without a circular ref.
        conf = cherrypy.config.get
        
        # Output config options to log
        if conf("server.log_config_options", True):
            cherrypy.config.outputConfigMap()
        
        # Hmmm...we *could* check config in _start instead, but I think
        # most people would like CP to fail before autoreload kicks in.
        err = cherrypy.WrongConfigValue
        for name, section in cherrypy.config.configs.iteritems():
            for k, v in section.iteritems():
                if k == "server.environment":
                    if v and v not in cherrypy.config.environments:
                        raise err("'%s' is not a registered environment." % v)
        
        if cherrypy.codecoverage:
            from cherrypy.lib import covercp
            covercp.start()
        
        # If sessions are stored in files and we
        # use threading, we need a lock on the file
        if (conf('server.thread_pool') > 1
            and conf('session.storage_type') == 'file'):
            cherrypy._sessionFileLock = threading.RLock()
        
        # set cgi.maxlen which will limit the size of POST request bodies
        cgi.maxlen = conf('server.max_request_size')
        
        # Set up the profiler if requested.
        if conf("profiling.on", False):
            ppath = conf("profiling.path", "")
            cherrypy.profiler = profiler.Profiler(ppath)
        else:
            cherrypy.profiler = None
        
        # Initialize the built in filters
        filters.init()
    
    def start(self):
        """Start the application server engine."""
        self.state = STARTING
        self.interrupt = None
        
        conf = cherrypy.config.get
        
        # Autoreload. Note that, if we're not starting our own HTTP server,
        # autoreload could do Very Bad Things when it calls sys.exit, but
        # deployers will just have to be educated and responsible for it.
        if conf('autoreload.on', False):
            try:
                freq = conf('autoreload.frequency', 1)
                autoreload.main(self._start, freq=freq)
            except KeyboardInterrupt:
                cherrypy.log("<Ctrl-C> hit: shutting down autoreloader", "ENGINE")
                self.stop()
            except SystemExit:
                cherrypy.log("SystemExit raised: shutting down autoreloader", "ENGINE")
                self.stop()
                # We must raise here: if this is a process spawned by
                # autoreload, then it must return its error code to
                # the parent.
                raise
            return
        
        self._start()
    
    def _start(self):
        for func in self.on_start_server_list:
            func()
        self.state = STARTED
    
    def block(self):
        """Block forever (wait for stop(), KeyboardInterrupt or SystemExit)."""
        try:
            while self.state != STOPPED:
                time.sleep(.1)
                if self.interrupt:
                    raise self.interrupt
        except KeyboardInterrupt:
            cherrypy.log("<Ctrl-C> hit: shutting down app server", "ENGINE")
            self.stop()
        except SystemExit:
            cherrypy.log("SystemExit raised: shutting down app server", "ENGINE")
            self.stop()
            raise
        except:
            # Don't bother logging, since we're going to re-raise.
            self.interrupt = sys.exc_info()[1]
            self.stop()
            raise
    
    def stop(self):
        """Stop the application server engine."""
        for thread_ident, i in self.seen_threads.iteritems():
            for func in self.on_stop_thread_list:
                func(i)
        self.seen_threads.clear()
        
        for func in self.on_stop_server_list:
            func()
        
        self.state = STOPPED
        cherrypy.log("CherryPy shut down", "ENGINE")
    
    def restart(self):
        """Restart the application server engine."""
        self.stop()
        self.start()
    
    def wait(self):
        """Block the caller until ready to receive requests (or error)."""
        while not self.ready:
            time.sleep(.1)
            if self.interrupt:
                msg = "The CherryPy application server errored"
                raise cherrypy.NotReady(msg, "ENGINE")
    
    def _is_ready(self):
        return bool(self.state == STARTED)
    ready = property(_is_ready, doc="Return True if the server is ready to"
                                    " receive requests, False otherwise.")
    
    def request(self, clientAddress, remoteHost, scheme="http"):
        """Obtain an HTTP Request object.
        
        clientAddress: the (IP address, port) of the client
        remoteHost: the IP address of the client
        scheme: either "http" or "https"; defaults to "http"
        """
        if self.state == STOPPED:
            raise cherrypy.NotReady("The CherryPy server has stopped.")
        elif self.state == STARTING:
            raise cherrypy.NotReady("The CherryPy server could not start.")
        
        threadID = threading._get_ident()
        if threadID not in self.seen_threads:
            
            if cherrypy.codecoverage:
                from cherrypy.lib import covercp
                covercp.start()
            
            i = len(self.seen_threads) + 1
            self.seen_threads[threadID] = i
            
            for func in self.on_start_thread_list:
                func(i)
        
        r = self.request_class(clientAddress[0], clientAddress[1],
                               remoteHost, scheme)
        cherrypy.serving.request = r
        cherrypy.serving.response = self.response_class()
        return r