Add an unpatched version of xz, XZ Utils, to /trunk/deps/third_party

xz/src/liblzma/delta/delta_common.c

+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       delta_common.c
+/// \brief      Common stuff for Delta encoder and decoder
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "delta_common.h"
+#include "delta_private.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)
+{
+        // 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;
+        }
+
+        // Validate the options.
+        if (lzma_delta_coder_memusage(filters[0].options) == UINT64_MAX)
+                return LZMA_OPTIONS_ERROR;
+
+        // Set the delta distance.
+        const lzma_options_delta *opt = filters[0].options;
+        next->coder->distance = opt->dist;
+
+        // Initialize the rest of the variables.
+        next->coder->pos = 0;
+        memzero(next->coder->history, LZMA_DELTA_DIST_MAX);
+
+        // Initialize the next decoder in the chain, if any.
+        return lzma_next_filter_init(&next->coder->next,
+                        allocator, filters + 1);
+}
+
+
+extern uint64_t
+lzma_delta_coder_memusage(const void *options)
+{
+        const lzma_options_delta *opt = options;
+
+        if (opt == NULL || opt->type != LZMA_DELTA_TYPE_BYTE
+                        || opt->dist < LZMA_DELTA_DIST_MIN
+                        || opt->dist > LZMA_DELTA_DIST_MAX)
+                return UINT64_MAX;
+
+        return sizeof(lzma_coder);
+}