Re: package_rpm.bbclass: Replace shell provides/requires script with python version

[Mark Hatle <mark.hatle@windriver.com>]

On 4/26/12 2:54 PM, Richard Purdie wrote:
> The existing shell script is a fork bomb and forks off hundreds of
> grep/cur/wc calls as it reads from its input stream and iterates over
> the file data table for each line of input. This patch replaces the
> shell code with python code which doesn't exec anything and hence runs
> much faster without the exec() overhead. This speeds up rpm packaging
> considerably, as can be measured simply by timing it, or watching the
> processor utilisation.

Just an FYI, the intent was to replace this code completely with a patch to RPM 
when it got upgraded.  Then RPM could read in the dependencies directly and not 
have to worry about hacky script solutions.

Needless to say we're not yet at that point, so this is fine..  but hopefully 
we're getting closer.

--Mark

> Signed-off-by: Richard Purdie<richard.purdie@linuxfoundation.org>
> ---
> diff --git a/meta/classes/package_rpm.bbclass b/meta/classes/package_rpm.bbclass
> index ffe3b31..d90976b 100644
> --- a/meta/classes/package_rpm.bbclass
> +++ b/meta/classes/package_rpm.bbclass
> @@ -1004,8 +1004,9 @@ python do_package_rpm () {
>
>   	# Construct per file dependencies file
>   	def dump_filerdeps(varname, outfile, d):
> -		outfile.write("#!/bin/sh\n")
> -		outfile.write("\n# Dependency table\n")
> +		outfile.write("#!/usr/bin/env python\n\n")
> +		outfile.write("# Dependency table\n")
> +		outfile.write('deps = {\n')
>   		for pkg in packages.split():
>   			dependsflist_key = 'FILE' + varname + 'FLIST' + "_" + pkg
>   			dependsflist = (d.getVar(dependsflist_key, True) or "")
> @@ -1018,7 +1019,7 @@ python do_package_rpm () {
>   				file = file.replace("@tab@", "\t")
>   				file = file.replace("@space@", " ")
>   				file = file.replace("@at@", "@")
> -				outfile.write("#" + pkgd + file + "\t")
> +				outfile.write('"' + pkgd + file + '" : "')
>   				for dep in depends_dict:
>   					ver = depends_dict[dep]
>   					if dep and ver:
> @@ -1027,12 +1028,15 @@ python do_package_rpm () {
>   						outfile.write(dep + " " + ver + " ")
>   					else:
>   						outfile.write(dep + " ")
> -				outfile.write("\n")
> -		outfile.write("\n\nwhile read file_name ; do\n")
> -		outfile.write("\tlength=$(echo \"#${file_name}\t\" | wc -c )\n")
> -		outfile.write("\tline=$(grep \"^#${file_name}\t\" $0 | cut -c ${length}- )\n")
> -		outfile.write("\tprintf \"%s\\n\" ${line}\n")
> -		outfile.write("done\n")
> +				outfile.write('",\n')
> +		outfile.write('}\n\n')
> +		outfile.write("import sys\n")
> +		outfile.write("while 1:\n")
> +		outfile.write("\tline = sys.stdin.readline().strip()\n")
> +		outfile.write("\tif not line:\n")
> +		outfile.write("\t\tsys.exit(0)\n")
> +		outfile.write("\tif line in deps:\n")
> +		outfile.write("\t\tprint(deps[line] + '\\n')\n")
>
>   	# OE-core dependencies a.k.a. RPM requires
>   	outdepends = workdir + "/" + srcname + ".requires"
>
>