discover and configure modules in db/modules/

4 files changed, 114 insertions, 5 deletions

diff --git a/SConscript.buildinfo b/SConscript.buildinfo
index 3853adf2ba5..e366e7bd5da 100644
--- a/SConscript.buildinfo
+++ b/SConscript.buildinfo
@@ -31,7 +31,11 @@ namespace mongo {
 '''
 
 def generate_buildinfo(env, target, source, **kw):
-    contents = str(source[0]) % dict(git_version=buildscripts.utils.getGitVersion(),
+    git_version = buildscripts.utils.getGitVersion()
+    if env["MONGO_MODULES"]:
+        git_version += " modules: %s" % (", ".join(env["MONGO_MODULES"].keys()))
+
+    contents = str(source[0]) % dict(git_version=git_version,
                                      sys_info=getSysInfo())
     out = open(str(target[0]), 'wb')
     try:
diff --git a/SConstruct b/SConstruct
index a2231faa2c5..ea92db6bae6 100644
--- a/SConstruct
+++ b/SConstruct
@@ -26,6 +26,7 @@ import types
 import urllib
 import urllib2
 from buildscripts import utils
+from buildscripts import moduleconfig
 
 import libdeps
 
@@ -835,6 +836,14 @@ def doConfigure(myenv):
         myenv.Append( CPPDEFINES=[ "HEAP_CHECKING" ] )
         myenv.Append( CCFLAGS=["-fno-omit-frame-pointer"] )
 
+    # discover modules (subdirectories of db/modules/), and
+    # load the (python) module for each module's build.py
+    modules = moduleconfig.discover_modules('.')
+
+    # ask each module to configure itself, and return a
+    # dictionary of name => list_of_sources for each module.
+    env["MONGO_MODULES"] = moduleconfig.configure_modules(modules, conf, env)
+
     return conf.Finish()
 
 env = doConfigure( env )
diff --git a/buildscripts/moduleconfig.py b/buildscripts/moduleconfig.py
new file mode 100644
index 00000000000..15062c57c9f
--- /dev/null
+++ b/buildscripts/moduleconfig.py
@@ -0,0 +1,90 @@
+"""Utility functions for SCons to discover and configure
+MongoDB modules (sub-trees of db/modules/). This file exports
+two functions:
+
+    discover_modules, which returns a dictionary of module name
+        to the imported python module object for the module's
+        build.py file
+
+    configure_modules, which runs per-module configuration, and
+        is given the SCons environment, its own path, etc
+
+Each module must have a "build.py" script, which is expected to
+have a "configure" function, and optionally a "test" function
+if the module exposes per-module tests.
+"""
+
+__all__ = ('discover_modules', 'configure_modules')
+
+import imp
+from os import listdir
+from os.path import abspath, dirname, join, isdir, isfile
+
+def discover_modules(mongo_root):
+    """Scan <mongo_root>/db/modules/ for directories that
+    look like MongoDB modules (i.e. they contain a "build.py"
+    file), and return a dictionary of module name (the directory
+    name) to build.py python modules.
+    """
+    found_modules = {}
+
+    module_root = abspath(join(mongo_root, 'db', 'modules'))
+    for name in listdir(module_root):
+        root = join(module_root, name)
+        if '.' in name or not isdir(root):
+            continue
+
+        build_py = join(root, 'build.py')
+        module = None
+
+        if isfile(build_py):
+            print "adding module: %s" % name
+            fp = open(build_py, "r")
+            module = imp.load_module("module_" + name, fp, build_py, (".py", "r", imp.PY_SOURCE))
+            found_modules[name] = module
+            fp.close()
+
+    return found_modules
+
+def configure_modules(modules, conf, env):
+    """
+    Run the configure() function in the build.py python modules
+    for each module listed in the modules dictionary (as created
+    by discover_modules). The configure() function should use the
+    prepare the Mongo build system for building the module.
+
+    build.py files may specify a "customIncludes" flag, which, if
+    True, causes configure() to be called with three arguments:
+    the SCons Configure() object, the SCons environment, and an
+    empty list which should be modified in-place by the configure()
+    function; if false, configure() is called with only the first
+    two arguments, and the source files are discovered with a
+    glob against the <module_root>/src/*.cpp.
+
+    Returns a dictionary mapping module name to a list of source
+    files to be compiled for the module.
+    """
+    source_map = {}
+
+    for name, module in modules.items():
+        print "configuring module: %s" % name
+
+        root = dirname(module.__file__)
+        module_sources = []
+
+        if getattr(module, "customIncludes", False):
+            # then the module configures itself and its
+            # configure() takes 3 args
+            module.configure(conf, env, module_sources)
+        else:
+            # else we glob the files in the module's src/
+            # subdirectory, and its configure() takes 2 args
+            module.configure(conf, env)
+            module_sources.extend(Glob(join(root, "src/*.cpp")))
+
+        if not module_sources:
+            print "WARNING: no source files for module %s, module will not be built." % name
+        else:
+            source_map[name] = module_sources
+
+    return source_map
diff --git a/src/mongo/SConscript b/src/mongo/SConscript
index 94795ea2140..6e9230d6912 100644
--- a/src/mongo/SConscript
+++ b/src/mongo/SConscript
@@ -366,11 +366,17 @@ everythingButMongodAndMongosFiles = [
     ]
 env.StaticLibrary("notmongodormongos", everythingButMongodAndMongosFiles)
 
-modules = []
-moduleNames = []
-
 mongodOnlyFiles = [ "db/db.cpp", "db/compact.cpp", "db/commands/touch.cpp" ]
 
+# create a library per module, and add it as a dependency
+# for the mongod target; as of now, modules are only included
+# in mongod, as though they were part of serverOnlyFiles
+modules = []
+for modName, modSources in env["MONGO_MODULES"].items():
+    libName = "mod%s" % modName
+    env.StaticLibrary(libName, modSources)
+    modules.append(libName)
+
 # ----- TARGETS ------
 
 env.StaticLibrary("gridfs", "client/gridfs.cpp")
@@ -385,7 +391,7 @@ env.StaticLibrary("coreserver", coreServerFiles, LIBDEPS=["mongocommon", "script
 mongod = env.Install(
     '#/', env.Program( "mongod", mongodOnlyFiles,
                        LIBDEPS=["coreserver", "serveronly", "coredb", "ntservice",
-                                "mongodandmongos"],
+                                "mongodandmongos"] + modules,
                        _LIBDEPS='$_LIBDEPS_OBJS' ) )
 Default( mongod )