support a new field "parallel"

It is basically the parallel field from DEB_BUILD_OPTION which a special
value "auto" that is converted to the CPU count.

1 files changed, 9 insertions, 2 deletions

diff --git a/mdbp/common.py b/mdbp/common.py
index 77cbd33..097c7a3 100644
--- a/mdbp/common.py
+++ b/mdbp/common.py
@@ -7,6 +7,7 @@ import contextlib
 import hashlib
 import importlib.resources
 import json
+import multiprocessing
 import pathlib
 import tempfile
 import typing
@@ -57,8 +58,14 @@ def compute_env(build: JsonObject) -> typing.Dict[str, str]:
     """Compute the process environment from the build object."""
     env = dict(PATH="/usr/bin:/bin")
     env.update(build.get("environment", {}))
-    if build.get("options"):
-        env["DEB_BUILD_OPTIONS"] = " ".join(build["options"])
+    parallel = build.get("parallel")
+    if parallel == "auto":
+        parallel = "%d" % multiprocessing.cpu_count()
+    options = build.get("options", [])
+    if parallel:
+        options.append("parallel=" + parallel)
+    if options:
+        env["DEB_BUILD_OPTIONS"] = " ".join(options)
     return env
 
 class HashSumMismatch(Exception):