[SCRIPTS] Add json_2_tango_res

scripts/json_2_tango_res

+#!/usr/bin/env python
+
+import re
+import sys
+import argparse
+import json
+from contextlib import closing
+
+def load_json_config(f):
+    json_str = f.read()
+    data = json.loads(json_str)
+    keys = ['executable', 'server', 'class', 'device', 'config']
+    missing_keys = [k for k in keys if k not in data]
+    if missing_keys:
+        raise RuntimeError(f'Invalid JSON config: missing keys: {missing_keys}')
+        
+    json_lines = json_str.split('\n')
+    if json_lines[:1] != ['{'] or json_lines[-2:] != ['}', '']:
+        raise RuntimeError(f'Invalid JSON string: {json_str}')
+    config = None
+    indent = None
+    for l in json_lines[1:-2]:
+        if config is None:
+            entry_re = re.compile(r'(?P<indent>[ \t]+)"(?P<key>[^"]+)":[ \t]+'
+                                  r'("(?P<val>[^"]+)",|(\{))$')
+            m = entry_re.match(l)
+            if not m:
+                raise RuntimeError(f'Invalid JSON string: {json_str}')
+            if m['key'] != 'config':
+                if m['val'] != data[m['key']]:
+                    raise RuntimeError(f'JSON parse mismatch: {l}')
+            elif not m.group(5):
+                raise RuntimeError(f'Unexpected JSON config line: {l}')
+            else:
+                indent = m['indent']
+                config = [m.group(5)]
+            continue
+        if not l.startswith(indent):
+            raise RuntimeError(f'Unexpected JSON indent: {l}')
+        l = l[len(indent):]
+        config.append(l)
+        if l == '}':
+            break
+
+    data['config'] = config
+    return data
+    
+def dump_tango_res(data):
+    data['klass'] = data['class']
+    out = ['{executable}/{server}/DEVICE/{klass}: "{device}"'.format(**data)]
+    out += ['']
+    device_line = '{device}->config: '.format(**data)
+    indent = ' ' * len(device_line)
+    config = data['config']
+    term = ',\\'
+    out += [device_line + config[0] + term]
+    for l in config[1:-1]:
+        l = l.replace('"', '\\"')
+        out += [f'{indent}"{l}"{term}']
+    out += [indent + config[-1]]
+    return '\n'.join(out)
+
+def main():
+    parser = argparse.ArgumentParser(description=('Tango DB res -> '
+                                                  'JSON converter.'))
+    parser.add_argument('json_in', nargs='?', default='-',
+                        help='input JSON file name or "-" for stdin')
+    parser.add_argument('res_out', nargs='?', default='-',
+                        help='output Tango DB res. file name or "-" for stdout')
+
+    args = parser.parse_args()
+
+    out_file = sys.stdout if args.res_out == '-' else open(args.res_out, 'wt')
+    with closing(out_file):
+        in_file = sys.stdin if args.json_in == '-' else open(args.json_in, 'rt')
+        with closing(in_file):
+            data = load_json_config(in_file)
+        tango_res = dump_tango_res(data)
+        out_file.write(tango_res + '\n')
+    
+if __name__ == '__main__':
+    main()