>>>>> Joey Hess <[email protected]> writes:
>> + if (scalar(@filters) != 1 || $filters[0] !~ /^--lzma2=/) {
>> + die "Only LZMA2 is supported" ;
>> + die "Unkown dict size: $dict_size\n" if
(!defined($presets)) ;
>> + my $check_kwd = $check_kwd_of{$check_name} ;
>> + die "Unknown xz check: $check_name\n" if (!defined($check_kwd)) ;
> Could it just fall back to the old guessing behavior instead of dying?
It does, in reproducexz:
eval {
$possible_args = readxz($orig);
} ;
# If we get an error we fallback to guessing, otherwise, we should
# succeed with one of the proposed combinations
if (! $@) {
>> + foreach my $program (@supported_xz_programs) {
>> + # try to guess the xz arguments that are needed
>> foreach my $args (predictxzargs($possible_levels, $program)) {
>> - testvariant($orig, $tmpin, $program, @$args)
>> - && return $program, @$args;
>> + testvariant($orig, $tmpin, $program, @$args)
>> + && return $program, @$args;
> Your editor is replacing tabs with spaces..
I can fix that.
modified pristine-xz
=== modified file 'pristine-xz'
--- pristine-xz 2012-06-12 15:45:07 +0000
+++ pristine-xz 2012-06-19 07:47:17 +0000
@@ -101,6 +101,133 @@
print STDERR " pristine-xz [-vdkt] genxz delta file\n";
}
+sub assign_fields {
+ my ($hash, $labels, $fields) = @_ ;
+ @$hash{@$labels} = @$fields[1..scalar(@$labels)] ;
+}
+
+sub scan_xz_lvv_robot {
+ my ($filename) = @_ ;
+ # We need at least version 5.0 to get a proper '-lvv --robot'
+ # implemented
+ my $cmd = "xz -lvv --robot $filename" ;
+ my $ret = open (my $in, "$cmd |") || die "$cmd failed: $!";
+ my %xz = (file => {}, stream => {}, blocks => [],
+ summary => {}, totals => {}) ;
+ my (%file, %stream, @blocks, %summary, %totals) ;
+ my @file_labels = qw{nb_streams nb_blocks compressed uncompressed
+ ratio checks padding_size} ;
+ my @stream_labels =
+ qw{stream_num nb_blocks compressed_offset uncompressed_offset
+ compressed_size uncompressed_size ratio check_name
+ padding_size};
+ my @block_labels =
+ qw{stream_num block_in_stream block_in_file compressed_offset
+ uncompressed_offset compressed_size uncompressed_size ratio
+ check_name check_value header_size size_present_flags
+ actual_compressed_size uncompress_memory filter_chain} ;
+ my @summary_labels = qw{uncompressed_memory size_in_blocks} ;
+ my @totals_labels =
+ qw{nb_streams nb_blocks compressed_size uncompressed_size ratio
+ check_names padding_size nb_files uncompressed_memory
+ size_in_blocks} ;
+
+ while (my $line = <$in>) {
+ chomp $line ;
+ my @fields = split(/\t/, $line) ;
+ if ($fields[0] eq 'name') {
+ next ;
+ }
+ if ($fields[0] eq 'file') {
+ assign_fields($xz{file}, \@file_labels, \@fields) ;
+ next ;
+ }
+ if ($fields[0] eq 'stream') {
+ assign_fields($xz{stream}, \@stream_labels, \@fields) ;
+ next ;
+ }
+ if ($fields[0] eq 'block') {
+ my %block ;
+ assign_fields(\%block, \@block_labels, \@fields) ;
+ push @{$xz{blocks}}, \%block ;
+ next ;
+ }
+ if ($fields[0] eq 'summary') {
+ assign_fields($xz{summary}, \@summary_labels, \@fields);
+ next ;
+ }
+ if ($fields[0] eq 'totals') {
+ assign_fields($xz{totals}, \@totals_labels, \@fields) ;
+ next ;
+ }
+ }
+ close $in ;
+ return \%xz ;
+}
+
+sub predict_xz_args {
+ my ($xz) = @_ ;
+ my $presets = undef ;
+ my $block_split = undef ;
+ my $blocks = $xz->{blocks} ;
+ if (scalar(@$blocks)) {
+ # There is at least one block. We assume the same compression
+ # level for all blocks
+ my $block = $blocks->[0] ;
+ my @filters = split(/,/, $block->{filter_chain}) ;
+ if (scalar(@filters) != 1 || $filters[0] !~ /^--lzma2=/) {
+ die "Only LZMA2 is supported" ;
+ }
+ # Deduce the presets from the dict size
+ if ($filters[0] =~ /--lzma2=dict=(.*)/) {
+ my $dict_size = $1 ;
+ my %lzma2_presets_from_dict_size_of =
+ ('256KiB' => ['0'],
+ '1Mib' => ['1'],
+ '2MiB' => ['2'],
+ '4MiB' => ['4', '3'],
+ # Put 6 before 5 as it's the default and is
+ # more likely to be right
+ '8MiB' => ['6', '5'],
+ '16MiB' => ['7'],
+ '32MiB' => ['8'],
+ '64MiB' => ['9'],
+ ) ;
+ $presets = $lzma2_presets_from_dict_size_of{$dict_size};
+ die "Unkown dict size: $dict_size\n"
+ if (!defined($presets)) ;
+ }
+ if (scalar(@$blocks) > 1) {
+ # Gather the block uncompressed sizes
+ $block_split = join(',', map {$_->{uncompressed_size}}
+ @$blocks) ;
+ }
+ }
+ # FIXME: none is missing
+ my %check_kwd_of =
+ (CRC32 => 'crc32',
+ CRC64 => 'crc64',
+ 'SHA-256' => 'sha256',
+ ) ;
+ my $check_name = $xz->{stream}->{check_name} ;
+ my $check_kwd = $check_kwd_of{$check_name} ;
+ die "Unknown xz check: $check_name\n" if (!defined($check_kwd)) ;
+
+ my $possible_args = [] ;
+ my $common = ["--check=$check_kwd", "-z"] ;
+ # FIXME: --block-split is not (yet) part of xz-utils upstream
+ if (0 && defined($block_split)) {
+ # We put the block list in front of the parameters to make it
+ # easier to filter it later.
+ unshift @$common, "--block-split=$block_split" ;
+ }
+ foreach my $preset (@$presets) {
+ push @$possible_args, [@$common, "-$preset"] ;
+ push @$possible_args, [@$common, "-${preset}e"] ;
+ }
+ return $possible_args ;
+}
+
sub readxz {
my $filename = shift;
@@ -108,6 +235,22 @@
error "This is not a valid xz archive.";
}
+ # This will guess the compression level, check and blocks from the file.
+ # More info is still needed if the level used was 3/4 or 5/6 (see
+ # lzma2_presets_from_dict_size_of in predict_xz_args) or if --extreme
+ # was used. We output possible args for each combination in this case.
+ my $xz = scan_xz_lvv_robot($filename) ;
+ my $possible_args = predict_xz_args($xz) ;
+ return $possible_args ;
+}
+
+sub predictxzlevels {
+ my $filename = shift;
+
+ if (! is_xz($filename)) {
+ error "This is not a valid xz archive.";
+ }
+
# XXX We don't currently have a way to guess the level from the
# file format, as this level only presets several other tunables.
# Correct handling would involve finding as many preset values as
@@ -155,21 +298,37 @@
my $orig=shift;
my $wd=tempdir();
-
+
my $tmpin="$wd/test";
doit_redir($orig, $tmpin, "xz", "-dc");
# read fields from xz headers
- my ($possible_levels) = readxz($orig);
+ my $possible_args ;
+ eval {
+ $possible_args = readxz($orig);
+ } ;
+ # If we get an error we fallback to guessing, otherwise, we should
+ # succeed with one of the proposed combinations
+ if (! $@) {
+ foreach my $program (@supported_xz_programs) {
+ foreach my $args (@$possible_args) {
+ testvariant($orig, $tmpin, $program, @$args)
+ && return $program, @$args;
+ }
+ }
+ } else {
+ # Fallback to guessing
+ my ($possible_levels) = predictxzlevels($orig);
- foreach my $program (@supported_xz_programs) {
- # try to guess the xz arguments that are needed by the
- # header information
- foreach my $args (predictxzargs($possible_levels, $program)) {
- testvariant($orig, $tmpin, $program, @$args)
- && return $program, @$args;
+ foreach my $program (@supported_xz_programs) {
+ # try to guess the xz arguments that are needed
+ foreach my $args (predictxzargs($possible_levels,
+ $program)) {
+ testvariant($orig, $tmpin, $program, @$args)
+ && return $program, @$args;
+ }
}
- }
+ }
print STDERR "pristine-xz failed to reproduce build of $orig\n";
print STDERR "(Please file a bug report.)\n";
