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-rw-r--r--src/liblzma/delta/Makefile.am34
-rw-r--r--src/liblzma/delta/delta_common.c66
-rw-r--r--src/liblzma/delta/delta_common.h44
-rw-r--r--src/liblzma/delta/delta_decoder.c82
-rw-r--r--src/liblzma/delta/delta_decoder.h32
-rw-r--r--src/liblzma/delta/delta_encoder.c119
-rw-r--r--src/liblzma/delta/delta_encoder.h30
7 files changed, 407 insertions, 0 deletions
diff --git a/src/liblzma/delta/Makefile.am b/src/liblzma/delta/Makefile.am
new file mode 100644
index 00000000..fc09f5b8
--- /dev/null
+++ b/src/liblzma/delta/Makefile.am
@@ -0,0 +1,34 @@
+##
+## Copyright (C) 2008 Lasse Collin
+##
+## This library is free software; you can redistribute it and/or
+## modify it under the terms of the GNU Lesser General Public
+## License as published by the Free Software Foundation; either
+## version 2.1 of the License, or (at your option) any later version.
+##
+## This library is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+## Lesser General Public License for more details.
+##
+
+noinst_LTLIBRARIES = libdelta.la
+libdelta_la_CPPFLAGS = \
+ -I@top_srcdir@/src/liblzma/api \
+ -I@top_srcdir@/src/liblzma/common
+
+libdelta_la_SOURCES = \
+ delta_common.c \
+ delta_common.h
+
+if COND_ENCODER_DELTA
+libdelta_la_SOURCES += \
+ delta_encoder.c \
+ delta_encoder.h
+endif
+
+if COND_DECODER_DELTA
+libdelta_la_SOURCES += \
+ delta_decoder.c \
+ delta_decoder.h
+endif
diff --git a/src/liblzma/delta/delta_common.c b/src/liblzma/delta/delta_common.c
new file mode 100644
index 00000000..d40e0c7f
--- /dev/null
+++ b/src/liblzma/delta/delta_common.c
@@ -0,0 +1,66 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file delta_common.c
+/// \brief Common stuff for Delta encoder and decoder
+//
+// Copyright (C) 2007 Lasse Collin
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// Lesser General Public License for more details.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "delta_common.h"
+
+
+static void
+delta_coder_end(lzma_coder *coder, lzma_allocator *allocator)
+{
+ lzma_next_end(&coder->next, allocator);
+ lzma_free(coder, allocator);
+ return;
+}
+
+
+extern lzma_ret
+lzma_delta_coder_init(lzma_next_coder *next, lzma_allocator *allocator,
+ const lzma_filter_info *filters, lzma_code_function code)
+{
+ // Allocate memory for the decoder if needed.
+ if (next->coder == NULL) {
+ next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
+ if (next->coder == NULL)
+ return LZMA_MEM_ERROR;
+
+ // End function is the same for encoder and decoder.
+ next->end = &delta_coder_end;
+ next->coder->next = LZMA_NEXT_CODER_INIT;
+ }
+
+ // Coding function is different for encoder and decoder.
+ next->code = code;
+
+ // Set the delta distance.
+ if (filters[0].options == NULL)
+ return LZMA_PROG_ERROR;
+ next->coder->distance = ((lzma_options_delta *)(filters[0].options))
+ ->distance;
+ if (next->coder->distance < LZMA_DELTA_DISTANCE_MIN
+ || next->coder->distance > LZMA_DELTA_DISTANCE_MAX)
+ return LZMA_HEADER_ERROR;
+
+ // Initialize the rest of the variables.
+ next->coder->pos = 0;
+ memzero(next->coder->history, LZMA_DELTA_DISTANCE_MAX);
+
+ // Initialize the next decoder in the chain, if any.
+ return lzma_next_filter_init(&next->coder->next,
+ allocator, filters + 1);
+}
diff --git a/src/liblzma/delta/delta_common.h b/src/liblzma/delta/delta_common.h
new file mode 100644
index 00000000..1d58899d
--- /dev/null
+++ b/src/liblzma/delta/delta_common.h
@@ -0,0 +1,44 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file delta_common.h
+/// \brief Common stuff for Delta encoder and decoder
+//
+// Copyright (C) 2007 Lasse Collin
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// Lesser General Public License for more details.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef LZMA_DELTA_COMMON_H
+#define LZMA_DELTA_COMMON_H
+
+#include "common.h"
+
+struct lzma_coder_s {
+ /// Next coder in the chain
+ lzma_next_coder next;
+
+ /// Delta distance
+ size_t distance;
+
+ /// Position in history[]
+ uint8_t pos;
+
+ /// Buffer to hold history of the original data
+ uint8_t history[LZMA_DELTA_DISTANCE_MAX];
+};
+
+
+extern lzma_ret lzma_delta_coder_init(
+ lzma_next_coder *next, lzma_allocator *allocator,
+ const lzma_filter_info *filters, lzma_code_function code);
+
+#endif
diff --git a/src/liblzma/delta/delta_decoder.c b/src/liblzma/delta/delta_decoder.c
new file mode 100644
index 00000000..ee22ba02
--- /dev/null
+++ b/src/liblzma/delta/delta_decoder.c
@@ -0,0 +1,82 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file delta_decoder.c
+/// \brief Delta filter decoder
+//
+// Copyright (C) 2007, 2008 Lasse Collin
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// Lesser General Public License for more details.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "delta_decoder.h"
+#include "delta_common.h"
+
+
+static void
+decode_buffer(lzma_coder *coder, uint8_t *buffer, size_t size)
+{
+ const size_t distance = coder->distance;
+
+ for (size_t i = 0; i < size; ++i) {
+ buffer[i] += coder->history[(distance + coder->pos) & 0xFF];
+ coder->history[coder->pos-- & 0xFF] = buffer[i];
+ }
+}
+
+
+static lzma_ret
+delta_decode(lzma_coder *coder, lzma_allocator *allocator,
+ const uint8_t *restrict in, size_t *restrict in_pos,
+ size_t in_size, uint8_t *restrict out,
+ size_t *restrict out_pos, size_t out_size, lzma_action action)
+{
+ assert(coder->next.code != NULL);
+
+ const size_t out_start = *out_pos;
+
+ const lzma_ret ret = coder->next.code(coder->next.coder, allocator,
+ in, in_pos, in_size, out, out_pos, out_size,
+ action);
+
+ decode_buffer(coder, out + out_start, *out_pos - out_start);
+
+ return ret;
+}
+
+
+extern lzma_ret
+lzma_delta_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
+ const lzma_filter_info *filters)
+{
+ return lzma_delta_coder_init(next, allocator, filters, &delta_decode);
+}
+
+
+extern lzma_ret
+lzma_delta_props_decode(void **options, lzma_allocator *allocator,
+ const uint8_t *props, size_t props_size)
+{
+ if (props_size != 1)
+ return LZMA_HEADER_ERROR;
+
+ lzma_options_delta *opt
+ = lzma_alloc(sizeof(lzma_options_delta), allocator);
+ if (opt == NULL)
+ return LZMA_MEM_ERROR;
+
+ opt->type = LZMA_DELTA_TYPE_BYTE;
+ opt->distance = props[0] + 1;
+
+ *options = opt;
+
+ return LZMA_OK;
+}
diff --git a/src/liblzma/delta/delta_decoder.h b/src/liblzma/delta/delta_decoder.h
new file mode 100644
index 00000000..84852bf3
--- /dev/null
+++ b/src/liblzma/delta/delta_decoder.h
@@ -0,0 +1,32 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file delta_decoder.h
+/// \brief Delta filter decoder
+//
+// Copyright (C) 2007 Lasse Collin
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// Lesser General Public License for more details.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef LZMA_DELTA_DECODER_H
+#define LZMA_DELTA_DECODER_H
+
+#include "common.h"
+
+extern lzma_ret lzma_delta_decoder_init(lzma_next_coder *next,
+ lzma_allocator *allocator, const lzma_filter_info *filters);
+
+extern lzma_ret lzma_delta_props_decode(
+ void **options, lzma_allocator *allocator,
+ const uint8_t *props, size_t props_size);
+
+#endif
diff --git a/src/liblzma/delta/delta_encoder.c b/src/liblzma/delta/delta_encoder.c
new file mode 100644
index 00000000..d8f40287
--- /dev/null
+++ b/src/liblzma/delta/delta_encoder.c
@@ -0,0 +1,119 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file delta_encoder.c
+/// \brief Delta filter encoder
+//
+// Copyright (C) 2007, 2008 Lasse Collin
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// Lesser General Public License for more details.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "delta_encoder.h"
+#include "delta_common.h"
+
+
+/// Copies and encodes the data at the same time. This is used when Delta
+/// is the first filter in the chain (and thus the last filter in the
+/// encoder's filter stack).
+static void
+copy_and_encode(lzma_coder *coder,
+ const uint8_t *restrict in, uint8_t *restrict out, size_t size)
+{
+ const size_t distance = coder->distance;
+
+ for (size_t i = 0; i < size; ++i) {
+ const uint8_t tmp = coder->history[
+ (distance + coder->pos) & 0xFF];
+ coder->history[coder->pos-- & 0xFF] = in[i];
+ out[i] = in[i] - tmp;
+ }
+}
+
+
+/// Encodes the data in place. This is used when we are the last filter
+/// in the chain (and thus non-last filter in the encoder's filter stack).
+static void
+encode_in_place(lzma_coder *coder, uint8_t *buffer, size_t size)
+{
+ const size_t distance = coder->distance;
+
+ for (size_t i = 0; i < size; ++i) {
+ const uint8_t tmp = coder->history[
+ (distance + coder->pos) & 0xFF];
+ coder->history[coder->pos-- & 0xFF] = buffer[i];
+ buffer[i] -= tmp;
+ }
+}
+
+
+static lzma_ret
+delta_encode(lzma_coder *coder, lzma_allocator *allocator,
+ const uint8_t *restrict in, size_t *restrict in_pos,
+ size_t in_size, uint8_t *restrict out,
+ size_t *restrict out_pos, size_t out_size, lzma_action action)
+{
+ lzma_ret ret;
+
+ if (coder->next.code == NULL) {
+ const size_t in_avail = in_size - *in_pos;
+ const size_t out_avail = out_size - *out_pos;
+ const size_t size = MIN(in_avail, out_avail);
+
+ copy_and_encode(coder, in + *in_pos, out + *out_pos, size);
+
+ *in_pos += size;
+ *out_pos += size;
+
+ ret = action != LZMA_RUN && *in_pos == in_size
+ ? LZMA_STREAM_END : LZMA_OK;
+
+ } else {
+ const size_t out_start = *out_pos;
+
+ ret = coder->next.code(coder->next.coder, allocator,
+ in, in_pos, in_size, out, out_pos, out_size,
+ action);
+
+ encode_in_place(coder, out + out_start, *out_pos - out_start);
+ }
+
+ return ret;
+}
+
+
+extern lzma_ret
+lzma_delta_encoder_init(lzma_next_coder *next, lzma_allocator *allocator,
+ const lzma_filter_info *filters)
+{
+ return lzma_delta_coder_init(next, allocator, filters, &delta_encode);
+}
+
+
+extern lzma_ret
+lzma_delta_props_encode(const void *options, uint8_t *out)
+{
+ if (options == NULL)
+ return LZMA_PROG_ERROR;
+
+ const lzma_options_delta *opt = options;
+
+ // It's possible that newer liblzma versions will support larger
+ // distance values.
+ if (opt->type != LZMA_DELTA_TYPE_BYTE
+ || opt->distance < LZMA_DELTA_DISTANCE_MIN
+ || opt->distance > LZMA_DELTA_DISTANCE_MAX)
+ return LZMA_HEADER_ERROR;
+
+ out[0] = opt->distance - LZMA_DELTA_DISTANCE_MIN;
+
+ return LZMA_OK;
+}
diff --git a/src/liblzma/delta/delta_encoder.h b/src/liblzma/delta/delta_encoder.h
new file mode 100644
index 00000000..b8b29c61
--- /dev/null
+++ b/src/liblzma/delta/delta_encoder.h
@@ -0,0 +1,30 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file delta_encoder.h
+/// \brief Delta filter encoder
+//
+// Copyright (C) 2007 Lasse Collin
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// Lesser General Public License for more details.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef LZMA_DELTA_ENCODER_H
+#define LZMA_DELTA_ENCODER_H
+
+#include "common.h"
+
+extern lzma_ret lzma_delta_encoder_init(lzma_next_coder *next,
+ lzma_allocator *allocator, const lzma_filter_info *filters);
+
+extern lzma_ret lzma_delta_props_encode(const void *options, uint8_t *out);
+
+#endif
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-21 02:40:44 +0000