Improvements to view server checking

pretext/cli.py

@@ -612,30 +612,31 @@ def view(
         log.debug(e, exc_info=True)
         return
 
-    port = port or 8128
     # Call generate if flag is set
     if generate:
         try:
             target.generate_assets(only_changed=False)
         except Exception as e:
             log.info(f"Failed to generate assets: {e}")
             log.debug("", exc_info=True)
+    # Call build if flag is set
     if build:
         try:
             target.build()
         except Exception as e:
             log.info(f"Failed to build: {e}")
             log.debug("Exception info:\n##################\n", exc_info=True)
     # Start server if there isn't one running already:
-    if not utils.server_running(port=port) or restart_server:
+    used_port = utils.server_is_running()
+    if port or restart_server or not used_port:
         # First terminate any server that might be running
-        utils.stop_server()
+        utils.stop_server(port)
         # Start the server
         log.info("Starting server.")
         server = project.server_process(
             output_dir=target.output_dir_abspath(),
             access=access,
-            port=port,
+            port=port or 8128,
             launch=not no_launch,
         )
         server.start()
@@ -646,15 +647,15 @@ def view(
             log.info("Stopping server.")
             server.terminate()
             return
-
-    url = (
-        "http://localhost:"
-        + str(port)
-        + target.output_dir_abspath()
-        .as_posix()
-        .replace(project.abspath().as_posix(), "")
-    )
-    log.info(f"Viewing output for {target.name} at {url}")
+    else:
+        url = (
+            "http://localhost:"
+            + str(used_port)
+            + target.output_dir_abspath()
+            .as_posix()
+            .replace(project.abspath().as_posix(), "")
+        )
+        log.info(f"Viewing output for {target.name} at {url}")
 
 
 # pretext deploy

pretext/project/__init__.py

@@ -835,33 +835,6 @@ def generate_assets(
         self.save_asset_table(saved_asset_table)
         log.debug(f"Saved asset table to disk: {saved_asset_table}")
 
-    def view(
-        self,
-        access: t.Literal["public", "private"],
-        port: int = 8000,
-        watch: bool = False,
-        no_launch: bool = False,
-    ) -> None:
-        directory = self.output_dir_abspath()
-
-        if watch:
-            watch_directory = self.source_abspath()
-        else:
-            watch_directory = None
-        if not self.output_dir_abspath().exists():
-            log.error(f"The directory `{self.output_dir_abspath()}` does not exist.")
-            log.error(
-                f"Run `pretext view {self.name} -b` to build your project before viewing."
-            )
-            return
-
-        def watch_callback() -> None:
-            self.build()
-
-        utils.run_server(
-            directory, access, port, watch_directory, watch_callback, no_launch
-        )
-
 
 class Project(pxml.BaseXmlModel, tag="project", search_mode="unordered"):
     """

pretext/utils.py

@@ -15,7 +15,6 @@
 import tempfile
 import threading
 import psutil
-import urllib.request
 import watchdog.events
 import watchdog.observers
 import time
@@ -297,34 +296,6 @@ class TCPServer(socketserver.TCPServer):
             log.warning(f"Trying port {port} instead.\n")
 
 
-def run_server(
-    directory: Path,
-    access: t.Literal["public", "private"],
-    port: int,
-    watch_directory: t.Optional[Path] = None,
-    watch_callback: Callable[[], None] = lambda: None,
-    no_launch: bool = False,
-) -> None:
-    threading.Thread(
-        target=lambda: serve_forever(directory, access, port, no_launch), daemon=True
-    ).start()
-    if watch_directory is not None:
-        log.info(f"\nWatching for changes in `{watch_directory}` ...\n")
-        event_handler = HTMLRebuildHandler(watch_callback)
-        observer = watchdog.observers.Observer()
-        observer.schedule(event_handler, watch_directory, recursive=True)
-        observer.start()
-    try:
-        while True:
-            time.sleep(1)
-    except KeyboardInterrupt:
-        log.info("\nClosing server...")
-        if watch_directory is not None:
-            observer.stop()
-    if watch_directory is not None:
-        observer.join()
-
-
 # Info on namespaces: http://lxml.de/tutorial.html#namespaces
 NSMAP = {
     "xi": "http://www.w3.org/2001/XInclude",
@@ -714,39 +685,49 @@ def retrieve(temp: Path, folder: Path) -> None:
     shutil.rmtree(temp)
 
 
-def server_running(port: int) -> bool:
+def server_is_running() -> t.Optional[int]:
     """
-    Check if a pretext-view server is running already
+    Check if a pretext-view server is running already, and if so, return its port number.
     """
     # We look at all currently running processes and check if any are a pretext process that is a child of a pretext process.  This would only happen if we have run a `pretext view` command to start the server, so we can assume that this is the server we are looking for.
     for proc in psutil.process_iter():
         if proc.name() == "pretext" and proc.parent().name() == "pretext":
             log.debug(f"Found pretext server running with pid {proc.pid}")
-            if proc.status() == psutil.STATUS_STOPPED:
+            # Sometimes the process stops but doesn't get removed from the process list.  We check if the process is still running by checking its status.
+            if proc.status() not in [psutil.STATUS_RUNNING, psutil.STATUS_SLEEPING]:
                 log.debug("Server is stopped.")
-                return False
-            log.debug(f"Checking if port {port} is an html host:")
+                return None
+            # To get the port number, we look at the connections the process has open.  We assume that the server is running on the first port that is open.
             try:
-                with urllib.request.urlopen(f"http://localhost:{port}") as response:
-                    log.debug(f"Found html host running on port {port}")
-                    # We have found the right server if one of the files shown is project.ptx
-                    if "project.ptx" in response.read().decode("utf-8"):
-                        log.debug("Found project.ptx in html host.")
-                        return True
+                port = proc.connections()[0].laddr.port
+                log.debug(f"Server is running on port {port}")
+                return port
             except Exception as e:
-                log.debug(f"Did not find html: {e}")
-                log.debug(f"No html host running on port {port}")
-                return False
+                log.debug(f"Could not get port number. Exception: {e}", exc_info=True)
     log.debug("No pretext server found running.")
-    return False
+    return None
 
 
-def stop_server() -> None:
+def stop_server(port: t.Optional[int] = None) -> None:
     """
     Terminate a server running in the background.
     """
-    # As before, we look for a pretext process that is a child of a pretext process.  This time we terminate that process.
-    for proc in psutil.process_iter():
-        if proc.name() == "pretext" and proc.parent().name() == "pretext":
-            log.debug(f"Terminating process with PID {proc.pid}")
-            proc.terminate()
+    # If a port was passed, we look for a "pretext" process that has a connection on that port, and kill it if we find it.
+    if port is not None:
+        log.debug(f"Terminating server running on port {port}")
+        for proc in psutil.process_iter():
+            if len(proc.connections()) > 0:
+                if (
+                    proc.name() == "pretext"
+                    and proc.connections()[0].laddr.port == port
+                ):
+                    log.debug(
+                        f"Terminating process with PID {proc.pid} hosting on port {port}"
+                    )
+                    proc.terminate()
+    else:
+        # As before, we look for a pretext process that is a child of a pretext process.  This time we terminate that process.
+        for proc in psutil.process_iter():
+            if proc.name() == "pretext" and proc.parent().name() == "pretext":
+                log.debug(f"Terminating process with PID {proc.pid}")
+                proc.terminate()