diff options
| -rw-r--r-- | src/xz/coder.c | 63 |
1 files changed, 43 insertions, 20 deletions
diff --git a/src/xz/coder.c b/src/xz/coder.c index b5f7c392..268359a4 100644 --- a/src/xz/coder.c +++ b/src/xz/coder.c @@ -269,10 +269,9 @@ coder_set_compression_settings(void) if (memory_usage <= memory_limit) return; - // If --no-adjust was used or we didn't find LZMA1 or - // LZMA2 as the last filter, give an error immediately. - // --format=raw implies --no-adjust. - if (!opt_auto_adjust || opt_format == FORMAT_RAW) + // With --format=raw settings are never adjusted to meet + // the memory usage limit. + if (opt_format == FORMAT_RAW) memlimit_too_small(memory_usage); assert(opt_mode == MODE_COMPRESS); @@ -282,34 +281,58 @@ coder_set_compression_settings(void) if (opt_format == FORMAT_XZ && mt_options.threads > 1) { // Try to reduce the number of threads before // adjusting the compression settings down. - do { - // FIXME? The real single-threaded mode has - // lower memory usage, but it's not comparable - // because it doesn't write the size info - // into Block Headers. - if (--mt_options.threads == 0) - memlimit_too_small(memory_usage); - + while (mt_options.threads > 1) { + // Reduce the number of threads by one and check + // the memory usage. + --mt_options.threads; memory_usage = lzma_stream_encoder_mt_memusage( &mt_options); if (memory_usage == UINT64_MAX) message_bug(); - } while (memory_usage > memory_limit); + if (memory_usage <= memory_limit) { + // The memory usage is now low enough. + message(V_WARNING, _("Reduced the number of " + "threads from %s to %s to not exceed " + "the memory usage limit of %s MiB"), + uint64_to_str( + hardware_threads_get(), 0), + uint64_to_str(mt_options.threads, 1), + uint64_to_str(round_up_to_mib( + memory_limit), 2)); + return; + } + } + + // If --no-adjust was used, we cannot drop to single-threaded + // mode since it produces different compressed output. + // + // NOTE: In xz 5.2.x, --no-adjust also prevented reducing + // the number of threads. This changed in 5.3.3alpha. + if (!opt_auto_adjust) + memlimit_too_small(memory_usage); + + // Switch to single-threaded mode. It uses + // less memory than using one thread in + // the multithreaded mode but the output + // is also different. + hardware_threads_set(1); + memory_usage = lzma_raw_encoder_memusage(filters); + message(V_WARNING, _("Switching to single-threaded mode " + "to not exceed the memory usage limit of %s MiB"), + uint64_to_str(round_up_to_mib(memory_limit), 0)); - message(V_WARNING, _("Adjusted the number of threads " - "from %s to %s to not exceed " - "the memory usage limit of %s MiB"), - uint64_to_str(hardware_threads_get(), 0), - uint64_to_str(mt_options.threads, 1), - uint64_to_str(round_up_to_mib( - memory_limit), 2)); } # endif if (memory_usage <= memory_limit) return; + // Don't adjust LZMA2 or LZMA1 dictionary size if --no-adjust + // was specified as that would change the compressed output. + if (!opt_auto_adjust) + memlimit_too_small(memory_usage); + // Look for the last filter if it is LZMA2 or LZMA1, so we can make // it use less RAM. With other filters we don't know what to do. size_t i = 0; |