Initial project structure for procinfo Ruby/C extension

.gitignore

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+*.bundle
+*.so
+*.o
+ext/procinfo/Makefile
+*.gem

Gemfile

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+source 'https://rubygems.org'
+
+gem 'rake'
+gem 'rake-compiler'
+

Gemfile.lock

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+GEM
+  remote: https://rubygems.org/
+  specs:
+    rake (10.1.0)
+    rake-compiler (0.8.3)
+      rake
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  rake
+  rake-compiler

README.md

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+# procinfo
+
+A Ruby/C extension packaged as a gem that provides a more uniform interface
+to \*NIX process information.
+
+## Motivation
+
+I really needed to be able to get current RSS and max RSS information (and
+related process information) for a given process (which may or may not be
+the current running process). No Ruby library (as far as I found offered a
+consistent view of this information across the most \*NIX OSes).
+
+## Related Works
+
+`sys-proctable` is Ruby/C extension library that provides this to some
+degree. I wanted to use a different approach to this library and lower
+overhead, and compatibility of APIs exposed for all the supporting OSes.
+
+However, the above mentioned library may offer what you need.
+
+## License
+
+This code is shared under the BSD 3-clause license. See LICENSE for
+more information.
+
+## Author(s)
+
+* Susan Potter <me at susanpotter do net> (mbbx6spp on GitHub)
+
+## Contributor(s)
+
+N/A

Rakefile

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+require 'rake/testtask'
+require 'rake/clean'
+
+NAME = 'procinfo'
+EXT = RbConfig::CONFIG['DLEXT']
+
+# rule to build the extension: this says
+# that the extension should be rebuilt
+# after any change to the files in ext
+file "lib/#{NAME}/#{NAME}.#{EXT}" =>
+Dir.glob("ext/#{NAME}/*{.rb,.c}") do
+  Dir.chdir("ext/#{NAME}") do
+    # this does essentially the same thing
+    # as what RubyGems does
+    ruby "extconf.rb"
+    sh "make"
+  end
+  cp "ext/#{NAME}/#{NAME}.#{EXT}", "lib/#{NAME}"
+end
+
+# make the :test task depend on the shared
+# object, so it will be built automatically
+# before running the tests
+task :test => "lib/#{NAME}/#{NAME}.#{EXT}"
+
+# use 'rake clean' and 'rake clobber' to
+# easily delete generated files
+CLEAN.include("ext/**/*{.o,.log,.#{EXT}}")
+CLEAN.include('ext/**/Makefile')
+CLOBBER.include("lib/**/*.#{EXT}")
+
+Rake::TestTask.new do |t|
+  t.libs << 'test'
+end
+
+desc "Run tests"
+task :default => :test

bin/procinfo

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+#!/usr/bin/env ruby
+
+

ext/procinfo/extconf.rb

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+require 'mkmf'
+
+create_makefile('procinfo/procinfo')

ext/procinfo/procinfo.c

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+#include <ruby.h>
+
+#include <sys/resource.h>
+#include <sys/wait.h>
+
+static VALUE S_PROC_INFO = Qnil;
+
+// signatures
+void Init_procinfo(void);
+static VALUE procinfo_stats(VALUE);
+static VALUE _to_proc_stats_struct(const struct rusage *);
+static VALUE _to_time_value(struct timeval);
+
+static VALUE procinfo_stats(VALUE self) {
+  struct rusage usage;
+  if (getrusage(RUSAGE_SELF, &usage) == -1) {
+    rb_raise(rb_eRuntimeError, "getrusage call returned -1");
+  }
+
+  return _to_proc_stats_struct(&usage);
+}
+
+static VALUE _to_proc_stats_struct(const struct rusage *usage) {
+  VALUE user_time = _to_time_value(usage->ru_utime);
+  VALUE system_time = _to_time_value(usage->ru_stime);
+  VALUE max_rss = rb_int_new(usage->ru_maxrss);
+  VALUE shared_text_size = rb_int_new(usage->ru_ixrss);
+  VALUE unshared_data_size = rb_int_new(usage->ru_idrss);
+  VALUE unshared_stack_size = rb_int_new(usage->ru_isrss);
+  VALUE page_reclaims = rb_int_new(usage->ru_minflt);
+  VALUE page_faults = rb_int_new(usage->ru_majflt);
+  VALUE swaps = rb_int_new(usage->ru_nswap);
+  VALUE block_input_ops = rb_int_new(usage->ru_inblock);
+  VALUE block_output_ops = rb_int_new(usage->ru_oublock);
+  VALUE msgs_sent = rb_int_new(usage->ru_msgsnd);
+  VALUE msgs_recvd = rb_int_new(usage->ru_msgrcv);
+  VALUE signals_recvd = rb_int_new(usage->ru_nsignals);
+  VALUE voluntary_switches = rb_int_new(usage->ru_nvcsw);
+  VALUE involuntary_switches = rb_int_new(usage->ru_nivcsw);
+  return rb_struct_new(S_PROC_INFO,
+    user_time,              // usage->ru_utime
+    system_time,            // usage->ru_stime
+    max_rss,                // usage->ru_maxrss
+    shared_text_size,       // usage->ru_ixrss
+    unshared_data_size,     // usage->ru_idrss
+    unshared_stack_size,    // usage->ru_isrss
+    page_reclaims,          // usage->ru_minflt
+    page_faults,            // usage->ru_majflt
+    swaps,                  // usage->ru_nswap
+    block_input_ops,        // usage->ru_inblock
+    block_output_ops,       // usage->ru_oublock
+    msgs_sent,              // usage->ru_msgsnd
+    msgs_recvd,             // usage->ru_msgrcv
+    signals_recvd,          // usage->ru_nsignals
+    voluntary_switches,     // usage->ru_nvcsw
+    involuntary_switches,   // usage->ru_nivcsw
+    NULL);
+}
+
+static VALUE _to_time_value(struct timeval t) {
+  double time = t.tv_sec + t.tv_usec / 1000000.0;
+  return rb_float_new(time);
+}
+
+// Initialization function to setup struct and module method
+void Init_procinfo(void) {
+  VALUE M_PROCESS = rb_define_module("Process");
+  S_PROC_INFO = rb_struct_define("ProcStats",
+                  "user_time", "system_time", "max_rss",
+                  "shared_text_size", "unshared_data_size",
+                  "unshared_stack_size", "page_reclaims", "page_faults",
+                  "swaps", "block_input_ops", "block_output_ops",
+                  "msgs_sent", "msgs_recvd", "signals_recvd",
+                  "voluntary_switches", "involuntary_switches", NULL);
+
+  rb_const_set(M_PROCESS, rb_intern("ProcStats"), S_PROC_INFO);
+  rb_define_singleton_method(M_PROCESS, "stats", procinfo_stats, 0);
+}

lib/procinfo.rb

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+require 'procinfo/procinfo'

procinfo.gemspec

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+Gem::Specification.new do |s|
+  s.name = 'procinfo'
+  s.version = '0.1.0'
+  s.authors = ['Susan Potter']
+  s.summary = 'Provide cross *NIX OS uniform interface to process info'
+  s.files = Dir.glob('lib/**/*.rb') +
+    Dir.glob("ext/**/*.{c,h,rb}")
+  s.extensions = ['ext/procinfo/extconf.rb']
+  s.executables = ['procinfo']
+
+end

test/test_procinfo.rb

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+require 'test/unit'
+require 'procinfo'
+
+class ProcinfoTest < Test::Unit::TestCase
+  def test_stats
+    stats = Process.stats
+    puts stats.inspect
+    assert_equal Process::ProcStats, stats.class
+    assert stats.user_time > 0
+    assert stats.system_time > 0
+    assert stats.max_rss > 0
+  end
+end