[#1] winziprint.py: Add server mode

src/winziprint.py

@@ -1,18 +1,22 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
-from typing import Union
+from typing import TextIO
 import os
 import sys
 import time
 import traceback
 import gc
+import socketserver
+import io
+import signal
 
 import weasyprint
 import pypdf
 
 
 VERSION = __version__ = '0.1.0'
+SOCKET_ADDRESS = ('127.0.0.1', 30983)
 
 BATCH_SIZE = 10
 
@@ -21,7 +25,8 @@ def convert(input_files: list[str],
             output_files: str,
             encoding: str = None,
             padding: bool = False,
-            progress: bool = False) -> list[int]:
+            progress: bool = False,
+            out: TextIO = sys.stdout) -> list[int]:
     # it takes roughly 100ms to generate one document
     tmp_page_nums = []
     tmp_file_names = []
@@ -40,7 +45,7 @@ def convert(input_files: list[str],
                 documents.append(doc)
                 del html
                 if progress:
-                    print(f'progress: {i + n + i // BATCH_SIZE + 1}/{steps}', flush=True)
+                    print(f'progress: {i + n + i // BATCH_SIZE + 1}/{steps}', file=out, flush=True)
             all_pages = [p for doc in documents for p in doc.pages]
             tmp_file_name = f'{output_files}.{i:04}.part'
             documents[0].copy(all_pages).write_pdf(tmp_file_name)
@@ -49,8 +54,8 @@ def convert(input_files: list[str],
             del documents
             del all_pages
             gc.collect()
-            if progress and i < BATCH_SIZE:
+            if progress and i + BATCH_SIZE < len(html_files):
-                print(f'progress: {i + BATCH_SIZE + i // BATCH_SIZE + 1}/{steps}', flush=True)
+                print(f'progress: {i + BATCH_SIZE + i // BATCH_SIZE + 1}/{steps}', file=out, flush=True)
 
         merger = pypdf.PdfWriter()
         i = 0
@@ -76,51 +81,68 @@ def convert(input_files: list[str],
                 os.remove(pdf)
 
     if progress:
-        print(f'progress: {steps}/{steps}', flush=True)
+        print(f'progress: {steps}/{steps}', file=out, flush=True)
 
     return page_nums
 
 
-def _wrapper_convert(args: list[str], encoding: str = None, padding: bool = False, progress: bool = False) -> None:
+def _wrapper_convert(args: list[str],
+                     encoding: str = None,
+                     padding: bool = False,
+                     progress: bool = False,
+                     out: TextIO = sys.stdout) -> None:
     try:
         if len(args) < 2:
-            print(f'error: Too few arguments', flush=True)
+            print(f'error: Too few arguments', file=out, flush=True)
             return
         inputs = args[:-1]
         output = args[-1]
+        while len(inputs) > 0:
             if inputs[0] == '-2':
                 inputs.pop(0)
                 padding = True
+            elif inputs[0].startswith('-e'):
+                encoding = inputs.pop(0)[2:].strip()
+            elif inputs[0].startswith('-p'):
+                inputs.pop(0)
+                progress = True
+            else:
+                break
+        if len(inputs) == 0:
+            print(f'error: Too few arguments', file=out, flush=True)
+            return
         t0 = time.process_time()
-        pages = convert(inputs, output, encoding=encoding, padding=padding, progress=progress)
+        pages = convert(inputs, output, encoding=encoding, padding=padding, progress=progress, out=out)
         total = sum(p + 1 if padding and p % 2 != 0 else p for p in pages)
         t1 = time.process_time()
         print(f'success: '
               f'{len(args) - 1} documents, '
               f'{total} pages ({", ".join(str(p) for p in pages)}), '
               f'{t1 - t0:.1f} sec',
-              flush=True)
+              file=out, flush=True)
     except Exception as e:
         msg = str(e).replace('\n', ' ')
-        print(f'error: {msg}', flush=True)
+        print(f'error: {msg}', file=out, flush=True)
-        traceback.print_exception(e)
+        traceback.print_exception(e, file=sys.stderr)
     finally:
         gc.collect()
 
 
 def usage(error: bool = False) -> None:
-    print(f'usage: {sys.argv[0]} [-h] [-v] [-p] [-2] [-d DIR] [-e ENCODING] [ - | INPUT [INPUT...] OUTPUT ]\n\n'
+    print(f'usage: {sys.argv[0]} [-h] [-v] [-d DIR] [ -D | [-p] [-2] [-e ENCODING] [ - | INPUT [INPUT...] OUTPUT ] ]\n'
+          '\n'
           'options:\n'
           ' -h, --help          show this help message and exit\n'
-          ' -v, --version       show version and exit\n'
+          ' -V, --version       show version and exit\n'
+          ' -D, --daemon        run as a daemon and expose a named socket\n'
           ' -d, --directory     set the working directory\n'
           ' -e, --encoding      encoding of the input files\n'
           ' -2, --double-sided  pad documents to an even number of pages\n'
           ' -p, --progress      show progress updates\n'
           '\n'
           ' -                   use stdin for retrieving input and output file names (semi-colon-seperated)\n'
-          ' INPUT               name of an html input file\n'
+          ' INPUT               name of a html input file\n'
-          ' OUTPUT              name of an pdf output file',
+          ' OUTPUT              name of a pdf output file',
           file=sys.stderr if error else sys.stdout)
     sys.exit(1 if error else 0)
 
@@ -132,7 +154,7 @@ def version() -> None:
     sys.exit(0)
 
 
-def _get_arg(args: list[str], n1: str, n2: str = None, flag: bool = False) -> Union[None, str, bool]:
+def _get_arg(args: list[str], n1: str, n2: str = None, flag: bool = False) -> None | str | bool:
     v = None
     for n in [n1] + (n2 and [n2] or []):
         if flag:
@@ -150,16 +172,45 @@ def _get_arg(args: list[str], n1: str, n2: str = None, flag: bool = False) -> Un
     return v if not flag else v or False
 
 
+class ConnectionHandler(socketserver.StreamRequestHandler):
+    def handle(self):
+        try:
+            while True:
+                out = io.TextIOWrapper(self.wfile, encoding='utf-8')
+                for line in io.TextIOWrapper(self.rfile, encoding='utf-8'):
+                    _wrapper_convert(line.strip().split(';'), out=out)
+        except ValueError:
+            pass  # socket closed by client
+
+
 def main() -> None:
     args = sys.argv[1:]
     if len(args) == 0 or '-h' in args or '--help' in args:
         usage()
-    elif '-v' in args or '--version' in args:
+    elif '-V' in args or '--version' in args:
         version()
 
     working_dir = _get_arg(args, '-d', '--directory')
     if working_dir:
         os.chdir(working_dir)
+
+    if '-D' in args:
+        print('Running as daemon')
+        if len(args) != 1:
+            usage(True)
+        # a tcp server is used due to the lack of unix sockets on Windows
+        with socketserver.ThreadingTCPServer(SOCKET_ADDRESS, ConnectionHandler) as server:
+            def exit_gracefully(signum: int, frame) -> None:
+                raise KeyboardInterrupt()
+            signal.signal(signal.SIGINT, exit_gracefully)
+            signal.signal(signal.SIGTERM, exit_gracefully)
+            try:
+                server.serve_forever()
+            except KeyboardInterrupt:
+                print('', file=sys.stderr)
+        print('Shutting down')
+        return
+
     encoding = _get_arg(args, '-e', '--encoding')
     progress = _get_arg(args, '-p', '--progress', flag=True)
     double_sided = _get_arg(args, '-2', '--double-sided', flag=True)