python: Added the beginning of a client library for ashd.pdm.

diff --git a/python/ashd/pdmc.py b/python/ashd/pdmc.py
new file mode 100644 (file)
index 0000000..c056ea8
--- /dev/null
+++ b/python/ashd/pdmc.py
@@ -0,0 +1,97 @@
+"""Management for daemon processes
+
+This module provides some client support for the daemon management
+provided in the ashd.pdm module.
+"""
+
+import socket
+
+class protoerr(Exception):
+    pass
+
+def resolve(spec):
+    if isinstance(spec, socket.socket):
+        return spec
+    sk = None
+    try:
+        if "/" in spec:
+            sk = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+            sk.connect(spec)
+        elif spec.isdigit():
+            sk = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            sk.connect(("localhost", int(spec)))
+        elif ":" in spec:
+            sk = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            p = spec.rindex(":")
+            sk.connect((spec[:p], int(spec[p + 1:])))
+        else:
+            raise Exception("Unknown target specification %r" % spec)
+        rv = sk
+        sk = None
+    finally:
+        if sk is not None: sk.close()
+    return rv
+
+class client(object):
+    def __init__(self, sk, proto = None):
+        self.sk = resolve(sk)
+        self.buf = ""
+        line = self.readline()
+        if line != "+PDM1":
+            raise protoerr("Illegal protocol signature")
+        if proto is not None:
+            self.select(proto)
+
+    def close(self):
+        self.sk.close()
+
+    def readline(self):
+        while True:
+            p = self.buf.find("\n")
+            if p >= 0:
+                ret = self.buf[:p]
+                self.buf = self.buf[p + 1:]
+                return ret
+            ret = self.sk.recv(1024)
+            if ret == "":
+                return None
+            self.buf += ret
+
+    def select(self, proto):
+        if "\n" in proto:
+            raise Exception("Illegal protocol specified: %r" % proto)
+        self.sk.send(proto + "\n")
+        rep = self.readline()
+        if len(rep) < 1 or rep[0] != "+":
+            raise protoerr("Error reply when selecting protocol %s: %s" % (proto, rep[1:]))
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *excinfo):
+        self.close()
+        return False
+
+class replclient(client):
+    def __init__(self, sk):
+        super(replclient, self).__init__(sk, "repl")
+
+    def run(self, code):
+        while True:
+            ncode = code.replace("\n\n", "\n")
+            if ncode == code: break
+            code = ncode
+        while len(code) > 0 and code[-1] == "\n":
+            code = code[:-1]
+        self.sk.send(code + "\n\n")
+        buf = ""
+        while True:
+            ln = self.readline()
+            if ln[0] == " ":
+                buf += ln[1:] + "\n"
+            elif ln[0] == "+":
+                return buf
+            elif ln[0] == "-":
+                raise protoerr("Error reply: %s" % ln[1:])
+            else:
+                raise protoerr("Illegal reply: %s" % ln)