Provide a library for compact text node data

Some processes (e.g. nodefirmware update) warrant a different sort of
strategy to try to abbreviate, where collation falls short.  For this,
provide a columnar output that changes to line by line if stdout is not
a terminal.

confluent_client/confluent/screensqueeze.py

@@ -0,0 +1,85 @@
+# Copyright 2017 Lenovo
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import fcntl
+import sys
+import struct
+import termios
+
+def get_screenwidth():
+    return struct.unpack('hh', fcntl.ioctl(sys.stdout, termios.TIOCGWINSZ,
+                                           b'....'))[1]
+class ScreenPrinter(object):
+
+    def __init__(self, noderange, client, textlen=4):
+        self.squeeze = sys.stdout.isatty()
+        self.textlen = textlen
+        self.noderange = noderange
+        self.client = client
+        self.nodeoutput = {}
+        self.nodelist = []
+        maxlen = 0
+        for ans in self.client.read('/noderange/{0}/nodes/'.format(noderange)):
+            if 'error' in ans:
+                sys.stderr.write(ans['error'])
+                continue
+            nodename = ans['item']['href'][:-1]
+            if len(nodename) > maxlen:
+                maxlen = len(nodename)
+            self.nodelist.append(nodename)
+            self.nodeoutput[nodename] = ''
+        self.nodenamelen = maxlen
+        self.textlen = textlen
+        self.fieldwidth = maxlen + textlen + 1  # 1 for column
+
+    def set_output(self, node, text):
+        self.nodeoutput[node] = text
+        if len(text) >= self.textlen:
+            self.textlen = len(text) + 1
+            self.fieldwidth = self.textlen + self.nodenamelen + 1
+        self.drawscreen()
+
+    def drawscreen(self):
+        if self.squeeze:
+            currwidth = get_screenwidth()
+            numfields = currwidth // self.fieldwidth
+            fieldformat = '{{0:>{0}}}:{{1:{1}}}'.format(self.nodenamelen,
+                                                        self.textlen)
+            sys.stdout.write('\x1b[2J\x1b[;H')  # clear screen
+        else:
+            numfields = 1
+            fieldformat = '{0}: {1}'
+        currfields = 0
+        for node in self.nodelist:
+            if currfields >= numfields:
+                sys.stdout.write('\n')
+                currfields = 1
+            else:
+                currfields += 1
+            sys.stdout.write(fieldformat.format(node, self.nodeoutput[node]))
+        sys.stdout.write('\n')
+        sys.stdout.flush()
+
+
+
+
+
+if __name__ == '__main__':
+    import confluent.client as client
+    c = client.Command()
+    p = ScreenPrinter('n1-n13', c)
+    p.set_output('n3', 'Upload: 67%')
+
+
+