From c42e8003aeada4d3b8e128e4a051a5acd2791f14 Mon Sep 17 00:00:00 2001
From: Andrew Lazarus <lazarus@squareup.com>
Date: Wed, 27 Jan 2016 13:34:54 -0800
Subject: [PATCH] teach protoc-gen-ruby PB_{DUMP,LOAD}_REQUEST_BYTES

`PB_DUMP_REQUEST_BYTES=foo.bin protoc foo.proto --plugin=protoc-gen-gem=bin/protoc-gen-ruby --gem_out=.`
will dump the raw proto request bytes generated by protoc for foo.proto to foo.bin

`PB_LOAD_REQUEST_BYTES=foo.bin bin/protoc-gen-ruby`
will read the raw request bytes from foo.bin and print the generated
code (actually it is the code gen response proto, but it is still
readable) to STDOUT
---
 bin/protoc-gen-ruby | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/bin/protoc-gen-ruby b/bin/protoc-gen-ruby
index a84b1c1c..c15246dd 100755
--- a/bin/protoc-gen-ruby
+++ b/bin/protoc-gen-ruby
@@ -16,7 +16,23 @@ require 'protobuf/code_generator'
 STDIN.binmode
 STDOUT.binmode
 
-request_bytes = STDIN.read
+request_bytes = if ENV['PB_LOAD_REQUEST_BYTES']
+                  File.read(ENV['PB_LOAD_REQUEST_BYTES'])
+                else
+                  STDIN.read
+                end
+if ENV['PB_DUMP_REQUEST_BYTES']
+  dump_file = ENV['PB_DUMP_REQUEST_BYTES']
+  unless File.directory?(File.dirname(dump_file))
+    warn "PB_DUMP_REQUEST_BYTES=#{dump_file.inspect} is not a valid path for the request bytes"
+    warn "Usage: PB_DUMP_REQUEST_BYTES=/path/to/desired/dump/file.bin protoc blah.proto"
+    exit 1
+  end
+  File.open(dump_file, 'w') do |f|
+    f.print(request_bytes)
+  end
+  exit 1
+end
 code_generator = ::Protobuf::CodeGenerator.new(request_bytes)
 code_generator.eval_unknown_extensions!
 STDOUT.print(code_generator.response_bytes)