+"""Module for handling server-side-include formatted files
+
+This module is quite incomplete. I might complete it with more
+features as I need them. It will probably never be entirely compliant
+with Apache's version due to architectural differences.
+"""
+
+import sys, os, io, time, logging, functools
+from . import wsgiutil
+
+log = logging.getLogger("ssi")
+
+def parsecmd(text, p):
+ try:
+ while text[p].isspace(): p += 1
+ cmd = ""
+ while not text[p].isspace():
+ cmd += text[p]
+ p += 1
+ pars = {}
+ while True:
+ while text[p].isspace(): p += 1
+ if text[p:p + 3] == "-->":
+ return cmd, pars, p + 3
+ key = ""
+ while text[p].isalnum():
+ key += text[p]
+ p += 1
+ if key == "":
+ return None, {}, p
+ while text[p].isspace(): p += 1
+ if text[p] != '=':
+ continue
+ p += 1
+ while text[p].isspace(): p += 1
+ q = text[p]
+ if q != '"' and q != "'" and q != '`':
+ continue
+ val = ""
+ p += 1
+ while text[p] != q:
+ val += text[p]
+ p += 1
+ p += 1
+ pars[key] = val
+ except IndexError:
+ return None, {}, len(text)
+
+class context(object):
+ def __init__(self, out, root):
+ self.out = out
+ self.vars = {}
+ now = time.time()
+ self.vars["DOCUMENT_NAME"] = os.path.basename(root.path)
+ self.vars["DATE_GMT"] = time.asctime(time.gmtime(now))
+ self.vars["DATE_LOCAL"] = time.asctime(time.localtime(now))
+ self.vars["LAST_MODIFIED"] = time.asctime(time.localtime(root.mtime))
+
+class ssifile(object):
+ def __init__(self, path):
+ self.path = path
+ self.mtime = os.stat(self.path).st_mtime
+ with open(path) as fp:
+ self.parts = self.parse(fp.read())
+
+ def text(self, text, ctx):
+ ctx.out.write(text)
+
+ def echo(self, var, enc, ctx):
+ if var in ctx.vars:
+ ctx.out.write(enc(ctx.vars[var]))
+
+ def include(self, path, ctx):
+ try:
+ nest = getfile(os.path.join(os.path.dirname(self.path), path))
+ except Exception:
+ log.warning("%s: could not find included file %s" % (self.path, path))
+ return
+ nest.process(ctx)
+
+ def process(self, ctx):
+ for part in self.parts:
+ part(ctx)
+
+ def resolvecmd(self, cmd, pars):
+ if cmd == "include":
+ if "file" in pars:
+ return functools.partial(self.include, pars["file"])
+ elif "virtual" in pars:
+ # XXX: For now, just include the file as-is. Change
+ # when necessary.
+ return functools.partial(self.include, pars["virtual"])
+ else:
+ log.warning("%s: invalid `include' directive" % self.path)
+ return None
+ elif cmd == "echo":
+ if not "var" in pars:
+ log.warning("%s: invalid `echo' directive" % self.path)
+ return None
+ enc = wsgiutil.htmlquote
+ if "encoding" in pars:
+ if pars["encoding"] == "entity":
+ enc = wsgiutil.htmlquote
+ return functools.partial(self.echo, pars["var"], enc)
+ else:
+ log.warning("%s: unknown SSI command `%s'" % (self.path, cmd))
+ return None
+
+ def parse(self, text):
+ ret = []
+ p = 0
+ while True:
+ p2 = text.find("<!--#", p)
+ if p2 < 0:
+ ret.append(functools.partial(self.text, text[p:]))
+ return ret
+ ret.append(functools.partial(self.text, text[p:p2]))
+ cmd, pars, p = parsecmd(text, p2 + 5)
+ if cmd is not None:
+ cmd = self.resolvecmd(cmd, pars)
+ if cmd is not None:
+ ret.append(cmd)
+
+filecache = {}
+
+def getfile(path):
+ path = os.path.normpath(path)
+ cf = filecache.get(path)
+ if not cf:
+ cf = filecache[path] = ssifile(path)
+ elif os.stat(path).st_mtime != cf.mtime:
+ cf = filecache[path] = ssifile(path)
+ return cf
+
+def wsgi(env, startreq):
+ try:
+ if env["PATH_INFO"] != "":
+ return wsgiutil.simpleerror(env, startreq, 404, "Not Found", "The resource specified by the URL does not exist.")
+ root = getfile(env["SCRIPT_FILENAME"])
+ buf = io.StringIO()
+ root.process(context(buf, root))
+ except Exception:
+ return wsgituil.simpleerror(env, startreq, 500, "Internal Error", "The server encountered an unpexpected error while handling SSI.")
+ ret = buf.getvalue().encode("utf8")
+ startreq("200 OK", [("Content-Type", "text/html; charset=UTF-8"), ("Content-Length", str(len(ret)))])
+ return [ret]