2 files changed, 67 insertions, 0 deletions
diff --git a/asciifarm/common/tcommunicate.py b/asciifarm/common/tcommunicate.py
new file mode 100644
index 0000000..b1fc1b0
--- /dev/null
+++ b/asciifarm/common/tcommunicate.py
@@ -0,0 +1,32 @@
+
+HEADER_SIZE = 4
+
+
+# this module is for sending discree messages over TCP
+# this is achieved by prefixing all messages with their length
+# calls to send and recv will also keep attempting to send all data unless this proves impossible
+
+
+def send(sock, msg):
+    length = len(msg)
+    header = length.to_bytes(4, byteorder="big")
+    totalmsg = header + msg
+    sock.sendall(totalmsg)
+
+def receive(sock):
+    header = recvall(sock, 4) #sock.recv(4)
+    length = int.from_bytes(header, byteorder="big")
+    return recvall(sock, length)
+
+def recvall(sock, length):
+    chunks = []
+    bytes_recd = 0
+    while bytes_recd < length:
+        chunk = sock.recv(min(length - bytes_recd, 4096))
+        if chunk == b'':
+            break
+            #raise RuntimeError("socket connection broken")
+        chunks.append(chunk)
+        bytes_recd = bytes_recd + len(chunk)
+    return b''.join(chunks)
+    
diff --git a/asciifarm/common/utils.py b/asciifarm/common/utils.py
new file mode 100644
index 0000000..3df020c
--- /dev/null
+++ b/asciifarm/common/utils.py
@@ -0,0 +1,35 @@
+
+import os
+
+def clamp(val, lower, upper):
+    """ val if it's between lower and upper, else the closest of the two"""
+    return min(max(val, lower), upper)
+
+
+def concat(arr):
+    """Takes a list of sequences, returns the concatenation of the sequences """
+    if isinstance(arr[0], str):
+        return "".join(arr)
+    if isinstance(arr[0], bytes):
+        return b"".join(arr)
+    if isinstance(arr[0], list):
+        l = []
+        for s in arr:
+            l += s
+        return l
+    if isinstance(arr[0], tuple):
+        l = []
+        for s in arr:
+            l += s
+        return tuple(l)
+    else:
+        raise ValueError("type {} can't be concatenated".format(type(arr[0])))
+
+
+def writeFileSafe(filename, data, tempname=None):
+    if tempname == None:
+        tempname = filename + ".tempfile"
+    with open(tempname, 'w') as f:
+        f.write(data)
+    os.rename(tempname, filename)
+