bitbake: bitbake: Rework hash equivalence

Reworks the hash equivalence server to address performance issues that
were encountered with the REST mechanism used previously, particularly
during the heavy request load encountered during signature generation.
Notable changes are:

1) The server protocol is no longer HTTP based. Instead, it uses a
   simpler JSON over a streaming protocol link. This protocol has much
   lower overhead than HTTP since it eliminates the HTTP headers.
2) The hash equivalence server can either bind to a TCP port, or a Unix
   domain socket. Unix domain sockets are more efficient for local
   communication, and so are preferred if the user enables hash
   equivalence only for the local build. The arguments to the
   'bitbake-hashserve' command have been updated accordingly.
3) The value to which BB_HASHSERVE should be set to enable a local hash
   equivalence server is changed to "auto" instead of "localhost:0". The
   latter didn't make sense when the local server was using a Unix
   domain socket.
4) Clients are expected to keep a persistent connection to the server
   instead of creating a new connection each time a request is made for
   optimal performance.
5) Most of the client logic has been moved to the hashserve module in
   bitbake. This makes it easier to share the client code.
6) A new bitbake command has been added called 'bitbake-hashclient'.
   This command can be used to query a hash equivalence server, including
   fetching the statistics and running a performance stress test.
7) The table indexes in the SQLite database have been updated to
   optimize hash lookups. This change is backward compatible, as the
   database will delete the old indexes first if they exist.
8) The server has been reworked to use python async to maximize
   performance with persistently connected clients. This requires Python
   3.5 or later.

(Bitbake rev: 2124eec3a5830afe8e07ffb6f2a0df6a417ac973)

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 170 insertions, 0 deletions

diff --git a/bitbake/bin/bitbake-hashclient b/bitbake/bin/bitbake-hashclient
new file mode 100755
index 0000000000..29ab65f177
--- /dev/null
+++ b/bitbake/bin/bitbake-hashclient
@@ -0,0 +1,170 @@
+#! /usr/bin/env python3
+#
+# Copyright (C) 2019 Garmin Ltd.
+#
+# SPDX-License-Identifier: GPL-2.0-only
+#
+
+import argparse
+import hashlib
+import logging
+import os
+import pprint
+import sys
+import threading
+import time
+
+try:
+    import tqdm
+    ProgressBar = tqdm.tqdm
+except ImportError:
+    class ProgressBar(object):
+        def __init__(self, *args, **kwargs):
+            pass
+
+        def __enter__(self):
+            return self
+
+        def __exit__(self, *args, **kwargs):
+            pass
+
+        def update(self):
+            pass
+
+sys.path.insert(0, os.path.join(os.path.dirname(os.path.dirname(__file__)), 'lib'))
+
+import hashserv
+
+DEFAULT_ADDRESS = 'unix://./hashserve.sock'
+METHOD = 'stress.test.method'
+
+
+def main():
+    def handle_stats(args, client):
+        if args.reset:
+            s = client.reset_stats()
+        else:
+            s = client.get_stats()
+        pprint.pprint(s)
+        return 0
+
+    def handle_stress(args, client):
+        def thread_main(pbar, lock):
+            nonlocal found_hashes
+            nonlocal missed_hashes
+            nonlocal max_time
+
+            client = hashserv.create_client(args.address)
+
+            for i in range(args.requests):
+                taskhash = hashlib.sha256()
+                taskhash.update(args.taskhash_seed.encode('utf-8'))
+                taskhash.update(str(i).encode('utf-8'))
+
+                start_time = time.perf_counter()
+                l = client.get_unihash(METHOD, taskhash.hexdigest())
+                elapsed = time.perf_counter() - start_time
+
+                with lock:
+                    if l:
+                        found_hashes += 1
+                    else:
+                        missed_hashes += 1
+
+                    max_time = max(elapsed, max_time)
+                    pbar.update()
+
+        max_time = 0
+        found_hashes = 0
+        missed_hashes = 0
+        lock = threading.Lock()
+        total_requests = args.clients * args.requests
+        start_time = time.perf_counter()
+        with ProgressBar(total=total_requests) as pbar:
+            threads = [threading.Thread(target=thread_main, args=(pbar, lock), daemon=False) for _ in range(args.clients)]
+            for t in threads:
+                t.start()
+
+            for t in threads:
+                t.join()
+
+        elapsed = time.perf_counter() - start_time
+        with lock:
+            print("%d requests in %.1fs. %.1f requests per second" % (total_requests, elapsed, total_requests / elapsed))
+            print("Average request time %.8fs" % (elapsed / total_requests))
+            print("Max request time was %.8fs" % max_time)
+            print("Found %d hashes, missed %d" % (found_hashes, missed_hashes))
+
+        if args.report:
+            with ProgressBar(total=args.requests) as pbar:
+                for i in range(args.requests):
+                    taskhash = hashlib.sha256()
+                    taskhash.update(args.taskhash_seed.encode('utf-8'))
+                    taskhash.update(str(i).encode('utf-8'))
+
+                    outhash = hashlib.sha256()
+                    outhash.update(args.outhash_seed.encode('utf-8'))
+                    outhash.update(str(i).encode('utf-8'))
+
+                    client.report_unihash(taskhash.hexdigest(), METHOD, outhash.hexdigest(), taskhash.hexdigest())
+
+                    with lock:
+                        pbar.update()
+
+    parser = argparse.ArgumentParser(description='Hash Equivalence Client')
+    parser.add_argument('--address', default=DEFAULT_ADDRESS, help='Server address (default "%(default)s")')
+    parser.add_argument('--log', default='WARNING', help='Set logging level')
+
+    subparsers = parser.add_subparsers()
+
+    stats_parser = subparsers.add_parser('stats', help='Show server stats')
+    stats_parser.add_argument('--reset', action='store_true',
+                              help='Reset server stats')
+    stats_parser.set_defaults(func=handle_stats)
+
+    stress_parser = subparsers.add_parser('stress', help='Run stress test')
+    stress_parser.add_argument('--clients', type=int, default=10,
+                               help='Number of simultaneous clients')
+    stress_parser.add_argument('--requests', type=int, default=1000,
+                               help='Number of requests each client will perform')
+    stress_parser.add_argument('--report', action='store_true',
+                               help='Report new hashes')
+    stress_parser.add_argument('--taskhash-seed', default='',
+                               help='Include string in taskhash')
+    stress_parser.add_argument('--outhash-seed', default='',
+                               help='Include string in outhash')
+    stress_parser.set_defaults(func=handle_stress)
+
+    args = parser.parse_args()
+
+    logger = logging.getLogger('hashserv')
+
+    level = getattr(logging, args.log.upper(), None)
+    if not isinstance(level, int):
+        raise ValueError('Invalid log level: %s' % args.log)
+
+    logger.setLevel(level)
+    console = logging.StreamHandler()
+    console.setLevel(level)
+    logger.addHandler(console)
+
+    func = getattr(args, 'func', None)
+    if func:
+        client = hashserv.create_client(args.address)
+        # Try to establish a connection to the server now to detect failures
+        # early
+        client.connect()
+
+        return func(args, client)
+
+    return 0
+
+
+if __name__ == '__main__':
+    try:
+        ret = main()
+    except Exception:
+        ret = 1
+        import traceback
+        traceback.print_exc()
+    sys.exit(ret)