X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=lzma%2Fcommon%2Findex.c;fp=lzma%2Fcommon%2Findex.c;h=26e4e519bc800627089297a73ae6df0d9921f901;hb=32b8a6b26ed8843828e03e505d2256960bda0980;hp=0000000000000000000000000000000000000000;hpb=d48fc23a4bcf8ca3c406d6e8c8a6f8c6b0fa2f1e;p=zpackage diff --git a/lzma/common/index.c b/lzma/common/index.c new file mode 100644 index 0000000..26e4e51 --- /dev/null +++ b/lzma/common/index.c @@ -0,0 +1,1250 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file index.c +/// \brief Handling of .xz Indexes and some other Stream information +// +// Author: Lasse Collin +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#include "index.h" +#include "stream_flags_common.h" + + +/// \brief How many Records to allocate at once +/// +/// This should be big enough to avoid making lots of tiny allocations +/// but small enough to avoid too much unused memory at once. +#define INDEX_GROUP_SIZE 512 + + +/// \brief How many Records can be allocated at once at maximum +#define PREALLOC_MAX ((SIZE_MAX - sizeof(index_group)) / sizeof(index_record)) + + +/// \brief Base structure for index_stream and index_group structures +typedef struct index_tree_node_s index_tree_node; +struct index_tree_node_s { + /// Uncompressed start offset of this Stream (relative to the + /// beginning of the file) or Block (relative to the beginning + /// of the Stream) + lzma_vli uncompressed_base; + + /// Compressed start offset of this Stream or Block + lzma_vli compressed_base; + + index_tree_node *parent; + index_tree_node *left; + index_tree_node *right; +}; + + +/// \brief AVL tree to hold index_stream or index_group structures +typedef struct { + /// Root node + index_tree_node *root; + + /// Leftmost node. Since the tree will be filled sequentially, + /// this won't change after the first node has been added to + /// the tree. + index_tree_node *leftmost; + + /// The rightmost node in the tree. Since the tree is filled + /// sequentially, this is always the node where to add the new data. + index_tree_node *rightmost; + + /// Number of nodes in the tree + uint32_t count; + +} index_tree; + + +typedef struct { + lzma_vli uncompressed_sum; + lzma_vli unpadded_sum; +} index_record; + + +typedef struct { + /// Every Record group is part of index_stream.groups tree. + index_tree_node node; + + /// Number of Blocks in this Stream before this group. + lzma_vli number_base; + + /// Number of Records that can be put in records[]. + size_t allocated; + + /// Index of the last Record in use. + size_t last; + + /// The sizes in this array are stored as cumulative sums relative + /// to the beginning of the Stream. This makes it possible to + /// use binary search in lzma_index_locate(). + /// + /// Note that the cumulative summing is done specially for + /// unpadded_sum: The previous value is rounded up to the next + /// multiple of four before adding the Unpadded Size of the new + /// Block. The total encoded size of the Blocks in the Stream + /// is records[last].unpadded_sum in the last Record group of + /// the Stream. + /// + /// For example, if the Unpadded Sizes are 39, 57, and 81, the + /// stored values are 39, 97 (40 + 57), and 181 (100 + 181). + /// The total encoded size of these Blocks is 184. + /// + /// This is a flexible array, because it makes easy to optimize + /// memory usage in case someone concatenates many Streams that + /// have only one or few Blocks. + index_record records[]; + +} index_group; + + +typedef struct { + /// Every index_stream is a node in the tree of Sreams. + index_tree_node node; + + /// Number of this Stream (first one is 1) + uint32_t number; + + /// Total number of Blocks before this Stream + lzma_vli block_number_base; + + /// Record groups of this Stream are stored in a tree. + /// It's a T-tree with AVL-tree balancing. There are + /// INDEX_GROUP_SIZE Records per node by default. + /// This keeps the number of memory allocations reasonable + /// and finding a Record is fast. + index_tree groups; + + /// Number of Records in this Stream + lzma_vli record_count; + + /// Size of the List of Records field in this Stream. This is used + /// together with record_count to calculate the size of the Index + /// field and thus the total size of the Stream. + lzma_vli index_list_size; + + /// Stream Flags of this Stream. This is meaningful only if + /// the Stream Flags have been told us with lzma_index_stream_flags(). + /// Initially stream_flags.version is set to UINT32_MAX to indicate + /// that the Stream Flags are unknown. + lzma_stream_flags stream_flags; + + /// Amount of Stream Padding after this Stream. This defaults to + /// zero and can be set with lzma_index_stream_padding(). + lzma_vli stream_padding; + +} index_stream; + + +struct lzma_index_s { + /// AVL-tree containing the Stream(s). Often there is just one + /// Stream, but using a tree keeps lookups fast even when there + /// are many concatenated Streams. + index_tree streams; + + /// Uncompressed size of all the Blocks in the Stream(s) + lzma_vli uncompressed_size; + + /// Total size of all the Blocks in the Stream(s) + lzma_vli total_size; + + /// Total number of Records in all Streams in this lzma_index + lzma_vli record_count; + + /// Size of the List of Records field if all the Streams in this + /// lzma_index were packed into a single Stream (makes it simpler to + /// take many .xz files and combine them into a single Stream). + /// + /// This value together with record_count is needed to calculate + /// Backward Size that is stored into Stream Footer. + lzma_vli index_list_size; + + /// How many Records to allocate at once in lzma_index_append(). + /// This defaults to INDEX_GROUP_SIZE but can be overriden with + /// lzma_index_prealloc(). + size_t prealloc; + + /// Bitmask indicating what integrity check types have been used + /// as set by lzma_index_stream_flags(). The bit of the last Stream + /// is not included here, since it is possible to change it by + /// calling lzma_index_stream_flags() again. + uint32_t checks; +}; + + +static void +index_tree_init(index_tree *tree) +{ + tree->root = NULL; + tree->leftmost = NULL; + tree->rightmost = NULL; + tree->count = 0; + return; +} + + +/// Helper for index_tree_end() +static void +index_tree_node_end(index_tree_node *node, const lzma_allocator *allocator, + void (*free_func)(void *node, const lzma_allocator *allocator)) +{ + // The tree won't ever be very huge, so recursion should be fine. + // 20 levels in the tree is likely quite a lot already in practice. + if (node->left != NULL) + index_tree_node_end(node->left, allocator, free_func); + + if (node->right != NULL) + index_tree_node_end(node->right, allocator, free_func); + + free_func(node, allocator); + return; +} + + +/// Free the memory allocated for a tree. Each node is freed using the +/// given free_func which is either &lzma_free or &index_stream_end. +/// The latter is used to free the Record groups from each index_stream +/// before freeing the index_stream itself. +static void +index_tree_end(index_tree *tree, const lzma_allocator *allocator, + void (*free_func)(void *node, const lzma_allocator *allocator)) +{ + assert(free_func != NULL); + + if (tree->root != NULL) + index_tree_node_end(tree->root, allocator, free_func); + + return; +} + + +/// Add a new node to the tree. node->uncompressed_base and +/// node->compressed_base must have been set by the caller already. +static void +index_tree_append(index_tree *tree, index_tree_node *node) +{ + node->parent = tree->rightmost; + node->left = NULL; + node->right = NULL; + + ++tree->count; + + // Handle the special case of adding the first node. + if (tree->root == NULL) { + tree->root = node; + tree->leftmost = node; + tree->rightmost = node; + return; + } + + // The tree is always filled sequentially. + assert(tree->rightmost->uncompressed_base <= node->uncompressed_base); + assert(tree->rightmost->compressed_base < node->compressed_base); + + // Add the new node after the rightmost node. It's the correct + // place due to the reason above. + tree->rightmost->right = node; + tree->rightmost = node; + + // Balance the AVL-tree if needed. We don't need to keep the balance + // factors in nodes, because we always fill the tree sequentially, + // and thus know the state of the tree just by looking at the node + // count. From the node count we can calculate how many steps to go + // up in the tree to find the rotation root. + uint32_t up = tree->count ^ (UINT32_C(1) << bsr32(tree->count)); + if (up != 0) { + // Locate the root node for the rotation. + up = ctz32(tree->count) + 2; + do { + node = node->parent; + } while (--up > 0); + + // Rotate left using node as the rotation root. + index_tree_node *pivot = node->right; + + if (node->parent == NULL) { + tree->root = pivot; + } else { + assert(node->parent->right == node); + node->parent->right = pivot; + } + + pivot->parent = node->parent; + + node->right = pivot->left; + if (node->right != NULL) + node->right->parent = node; + + pivot->left = node; + node->parent = pivot; + } + + return; +} + + +/// Get the next node in the tree. Return NULL if there are no more nodes. +static void * +index_tree_next(const index_tree_node *node) +{ + if (node->right != NULL) { + node = node->right; + while (node->left != NULL) + node = node->left; + + return (void *)(node); + } + + while (node->parent != NULL && node->parent->right == node) + node = node->parent; + + return (void *)(node->parent); +} + + +/// Locate a node that contains the given uncompressed offset. It is +/// caller's job to check that target is not bigger than the uncompressed +/// size of the tree (the last node would be returned in that case still). +static void * +index_tree_locate(const index_tree *tree, lzma_vli target) +{ + const index_tree_node *result = NULL; + const index_tree_node *node = tree->root; + + assert(tree->leftmost == NULL + || tree->leftmost->uncompressed_base == 0); + + // Consecutive nodes may have the same uncompressed_base. + // We must pick the rightmost one. + while (node != NULL) { + if (node->uncompressed_base > target) { + node = node->left; + } else { + result = node; + node = node->right; + } + } + + return (void *)(result); +} + + +/// Allocate and initialize a new Stream using the given base offsets. +static index_stream * +index_stream_init(lzma_vli compressed_base, lzma_vli uncompressed_base, + uint32_t stream_number, lzma_vli block_number_base, + const lzma_allocator *allocator) +{ + index_stream *s = lzma_alloc(sizeof(index_stream), allocator); + if (s == NULL) + return NULL; + + s->node.uncompressed_base = uncompressed_base; + s->node.compressed_base = compressed_base; + s->node.parent = NULL; + s->node.left = NULL; + s->node.right = NULL; + + s->number = stream_number; + s->block_number_base = block_number_base; + + index_tree_init(&s->groups); + + s->record_count = 0; + s->index_list_size = 0; + s->stream_flags.version = UINT32_MAX; + s->stream_padding = 0; + + return s; +} + + +/// Free the memory allocated for a Stream and its Record groups. +static void +index_stream_end(void *node, const lzma_allocator *allocator) +{ + index_stream *s = node; + index_tree_end(&s->groups, allocator, &lzma_free); + lzma_free(s, allocator); + return; +} + + +static lzma_index * +index_init_plain(const lzma_allocator *allocator) +{ + lzma_index *i = lzma_alloc(sizeof(lzma_index), allocator); + if (i != NULL) { + index_tree_init(&i->streams); + i->uncompressed_size = 0; + i->total_size = 0; + i->record_count = 0; + i->index_list_size = 0; + i->prealloc = INDEX_GROUP_SIZE; + i->checks = 0; + } + + return i; +} + + +extern LZMA_API(lzma_index *) +lzma_index_init(const lzma_allocator *allocator) +{ + lzma_index *i = index_init_plain(allocator); + if (i == NULL) + return NULL; + + index_stream *s = index_stream_init(0, 0, 1, 0, allocator); + if (s == NULL) { + lzma_free(i, allocator); + return NULL; + } + + index_tree_append(&i->streams, &s->node); + + return i; +} + + +extern LZMA_API(void) +lzma_index_end(lzma_index *i, const lzma_allocator *allocator) +{ + // NOTE: If you modify this function, check also the bottom + // of lzma_index_cat(). + if (i != NULL) { + index_tree_end(&i->streams, allocator, &index_stream_end); + lzma_free(i, allocator); + } + + return; +} + + +extern void +lzma_index_prealloc(lzma_index *i, lzma_vli records) +{ + if (records > PREALLOC_MAX) + records = PREALLOC_MAX; + + i->prealloc = (size_t)(records); + return; +} + + +extern LZMA_API(uint64_t) +lzma_index_memusage(lzma_vli streams, lzma_vli blocks) +{ + // This calculates an upper bound that is only a little bit + // bigger than the exact maximum memory usage with the given + // parameters. + + // Typical malloc() overhead is 2 * sizeof(void *) but we take + // a little bit extra just in case. Using LZMA_MEMUSAGE_BASE + // instead would give too inaccurate estimate. + const size_t alloc_overhead = 4 * sizeof(void *); + + // Amount of memory needed for each Stream base structures. + // We assume that every Stream has at least one Block and + // thus at least one group. + const size_t stream_base = sizeof(index_stream) + + sizeof(index_group) + 2 * alloc_overhead; + + // Amount of memory needed per group. + const size_t group_base = sizeof(index_group) + + INDEX_GROUP_SIZE * sizeof(index_record) + + alloc_overhead; + + // Number of groups. There may actually be more, but that overhead + // has been taken into account in stream_base already. + const lzma_vli groups + = (blocks + INDEX_GROUP_SIZE - 1) / INDEX_GROUP_SIZE; + + // Memory used by index_stream and index_group structures. + const uint64_t streams_mem = streams * stream_base; + const uint64_t groups_mem = groups * group_base; + + // Memory used by the base structure. + const uint64_t index_base = sizeof(lzma_index) + alloc_overhead; + + // Validate the arguments and catch integer overflows. + // Maximum number of Streams is "only" UINT32_MAX, because + // that limit is used by the tree containing the Streams. + const uint64_t limit = UINT64_MAX - index_base; + if (streams == 0 || streams > UINT32_MAX || blocks > LZMA_VLI_MAX + || streams > limit / stream_base + || groups > limit / group_base + || limit - streams_mem < groups_mem) + return UINT64_MAX; + + return index_base + streams_mem + groups_mem; +} + + +extern LZMA_API(uint64_t) +lzma_index_memused(const lzma_index *i) +{ + return lzma_index_memusage(i->streams.count, i->record_count); +} + + +extern LZMA_API(lzma_vli) +lzma_index_block_count(const lzma_index *i) +{ + return i->record_count; +} + + +extern LZMA_API(lzma_vli) +lzma_index_stream_count(const lzma_index *i) +{ + return i->streams.count; +} + + +extern LZMA_API(lzma_vli) +lzma_index_size(const lzma_index *i) +{ + return index_size(i->record_count, i->index_list_size); +} + + +extern LZMA_API(lzma_vli) +lzma_index_total_size(const lzma_index *i) +{ + return i->total_size; +} + + +extern LZMA_API(lzma_vli) +lzma_index_stream_size(const lzma_index *i) +{ + // Stream Header + Blocks + Index + Stream Footer + return LZMA_STREAM_HEADER_SIZE + i->total_size + + index_size(i->record_count, i->index_list_size) + + LZMA_STREAM_HEADER_SIZE; +} + + +static lzma_vli +index_file_size(lzma_vli compressed_base, lzma_vli unpadded_sum, + lzma_vli record_count, lzma_vli index_list_size, + lzma_vli stream_padding) +{ + // Earlier Streams and Stream Paddings + Stream Header + // + Blocks + Index + Stream Footer + Stream Padding + // + // This might go over LZMA_VLI_MAX due to too big unpadded_sum + // when this function is used in lzma_index_append(). + lzma_vli file_size = compressed_base + 2 * LZMA_STREAM_HEADER_SIZE + + stream_padding + vli_ceil4(unpadded_sum); + if (file_size > LZMA_VLI_MAX) + return LZMA_VLI_UNKNOWN; + + // The same applies here. + file_size += index_size(record_count, index_list_size); + if (file_size > LZMA_VLI_MAX) + return LZMA_VLI_UNKNOWN; + + return file_size; +} + + +extern LZMA_API(lzma_vli) +lzma_index_file_size(const lzma_index *i) +{ + const index_stream *s = (const index_stream *)(i->streams.rightmost); + const index_group *g = (const index_group *)(s->groups.rightmost); + return index_file_size(s->node.compressed_base, + g == NULL ? 0 : g->records[g->last].unpadded_sum, + s->record_count, s->index_list_size, + s->stream_padding); +} + + +extern LZMA_API(lzma_vli) +lzma_index_uncompressed_size(const lzma_index *i) +{ + return i->uncompressed_size; +} + + +extern LZMA_API(uint32_t) +lzma_index_checks(const lzma_index *i) +{ + uint32_t checks = i->checks; + + // Get the type of the Check of the last Stream too. + const index_stream *s = (const index_stream *)(i->streams.rightmost); + if (s->stream_flags.version != UINT32_MAX) + checks |= UINT32_C(1) << s->stream_flags.check; + + return checks; +} + + +extern uint32_t +lzma_index_padding_size(const lzma_index *i) +{ + return (LZMA_VLI_C(4) - index_size_unpadded( + i->record_count, i->index_list_size)) & 3; +} + + +extern LZMA_API(lzma_ret) +lzma_index_stream_flags(lzma_index *i, const lzma_stream_flags *stream_flags) +{ + if (i == NULL || stream_flags == NULL) + return LZMA_PROG_ERROR; + + // Validate the Stream Flags. + return_if_error(lzma_stream_flags_compare( + stream_flags, stream_flags)); + + index_stream *s = (index_stream *)(i->streams.rightmost); + s->stream_flags = *stream_flags; + + return LZMA_OK; +} + + +extern LZMA_API(lzma_ret) +lzma_index_stream_padding(lzma_index *i, lzma_vli stream_padding) +{ + if (i == NULL || stream_padding > LZMA_VLI_MAX + || (stream_padding & 3) != 0) + return LZMA_PROG_ERROR; + + index_stream *s = (index_stream *)(i->streams.rightmost); + + // Check that the new value won't make the file grow too big. + const lzma_vli old_stream_padding = s->stream_padding; + s->stream_padding = 0; + if (lzma_index_file_size(i) + stream_padding > LZMA_VLI_MAX) { + s->stream_padding = old_stream_padding; + return LZMA_DATA_ERROR; + } + + s->stream_padding = stream_padding; + return LZMA_OK; +} + + +extern LZMA_API(lzma_ret) +lzma_index_append(lzma_index *i, const lzma_allocator *allocator, + lzma_vli unpadded_size, lzma_vli uncompressed_size) +{ + // Validate. + if (i == NULL || unpadded_size < UNPADDED_SIZE_MIN + || unpadded_size > UNPADDED_SIZE_MAX + || uncompressed_size > LZMA_VLI_MAX) + return LZMA_PROG_ERROR; + + index_stream *s = (index_stream *)(i->streams.rightmost); + index_group *g = (index_group *)(s->groups.rightmost); + + const lzma_vli compressed_base = g == NULL ? 0 + : vli_ceil4(g->records[g->last].unpadded_sum); + const lzma_vli uncompressed_base = g == NULL ? 0 + : g->records[g->last].uncompressed_sum; + const uint32_t index_list_size_add = lzma_vli_size(unpadded_size) + + lzma_vli_size(uncompressed_size); + + // Check that the file size will stay within limits. + if (index_file_size(s->node.compressed_base, + compressed_base + unpadded_size, s->record_count + 1, + s->index_list_size + index_list_size_add, + s->stream_padding) == LZMA_VLI_UNKNOWN) + return LZMA_DATA_ERROR; + + // The size of the Index field must not exceed the maximum value + // that can be stored in the Backward Size field. + if (index_size(i->record_count + 1, + i->index_list_size + index_list_size_add) + > LZMA_BACKWARD_SIZE_MAX) + return LZMA_DATA_ERROR; + + if (g != NULL && g->last + 1 < g->allocated) { + // There is space in the last group at least for one Record. + ++g->last; + } else { + // We need to allocate a new group. + g = lzma_alloc(sizeof(index_group) + + i->prealloc * sizeof(index_record), + allocator); + if (g == NULL) + return LZMA_MEM_ERROR; + + g->last = 0; + g->allocated = i->prealloc; + + // Reset prealloc so that if the application happens to + // add new Records, the allocation size will be sane. + i->prealloc = INDEX_GROUP_SIZE; + + // Set the start offsets of this group. + g->node.uncompressed_base = uncompressed_base; + g->node.compressed_base = compressed_base; + g->number_base = s->record_count + 1; + + // Add the new group to the Stream. + index_tree_append(&s->groups, &g->node); + } + + // Add the new Record to the group. + g->records[g->last].uncompressed_sum + = uncompressed_base + uncompressed_size; + g->records[g->last].unpadded_sum + = compressed_base + unpadded_size; + + // Update the totals. + ++s->record_count; + s->index_list_size += index_list_size_add; + + i->total_size += vli_ceil4(unpadded_size); + i->uncompressed_size += uncompressed_size; + ++i->record_count; + i->index_list_size += index_list_size_add; + + return LZMA_OK; +} + + +/// Structure to pass info to index_cat_helper() +typedef struct { + /// Uncompressed size of the destination + lzma_vli uncompressed_size; + + /// Compressed file size of the destination + lzma_vli file_size; + + /// Same as above but for Block numbers + lzma_vli block_number_add; + + /// Number of Streams that were in the destination index before we + /// started appending new Streams from the source index. This is + /// used to fix the Stream numbering. + uint32_t stream_number_add; + + /// Destination index' Stream tree + index_tree *streams; + +} index_cat_info; + + +/// Add the Stream nodes from the source index to dest using recursion. +/// Simplest iterative traversal of the source tree wouldn't work, because +/// we update the pointers in nodes when moving them to the destination tree. +static void +index_cat_helper(const index_cat_info *info, index_stream *this) +{ + index_stream *left = (index_stream *)(this->node.left); + index_stream *right = (index_stream *)(this->node.right); + + if (left != NULL) + index_cat_helper(info, left); + + this->node.uncompressed_base += info->uncompressed_size; + this->node.compressed_base += info->file_size; + this->number += info->stream_number_add; + this->block_number_base += info->block_number_add; + index_tree_append(info->streams, &this->node); + + if (right != NULL) + index_cat_helper(info, right); + + return; +} + + +extern LZMA_API(lzma_ret) +lzma_index_cat(lzma_index *restrict dest, lzma_index *restrict src, + const lzma_allocator *allocator) +{ + const lzma_vli dest_file_size = lzma_index_file_size(dest); + + // Check that we don't exceed the file size limits. + if (dest_file_size + lzma_index_file_size(src) > LZMA_VLI_MAX + || dest->uncompressed_size + src->uncompressed_size + > LZMA_VLI_MAX) + return LZMA_DATA_ERROR; + + // Check that the encoded size of the combined lzma_indexes stays + // within limits. In theory, this should be done only if we know + // that the user plans to actually combine the Streams and thus + // construct a single Index (probably rare). However, exceeding + // this limit is quite theoretical, so we do this check always + // to simplify things elsewhere. + { + const lzma_vli dest_size = index_size_unpadded( + dest->record_count, dest->index_list_size); + const lzma_vli src_size = index_size_unpadded( + src->record_count, src->index_list_size); + if (vli_ceil4(dest_size + src_size) > LZMA_BACKWARD_SIZE_MAX) + return LZMA_DATA_ERROR; + } + + // Optimize the last group to minimize memory usage. Allocation has + // to be done before modifying dest or src. + { + index_stream *s = (index_stream *)(dest->streams.rightmost); + index_group *g = (index_group *)(s->groups.rightmost); + if (g != NULL && g->last + 1 < g->allocated) { + assert(g->node.left == NULL); + assert(g->node.right == NULL); + + index_group *newg = lzma_alloc(sizeof(index_group) + + (g->last + 1) + * sizeof(index_record), + allocator); + if (newg == NULL) + return LZMA_MEM_ERROR; + + newg->node = g->node; + newg->allocated = g->last + 1; + newg->last = g->last; + newg->number_base = g->number_base; + + memcpy(newg->records, g->records, newg->allocated + * sizeof(index_record)); + + if (g->node.parent != NULL) { + assert(g->node.parent->right == &g->node); + g->node.parent->right = &newg->node; + } + + if (s->groups.leftmost == &g->node) { + assert(s->groups.root == &g->node); + s->groups.leftmost = &newg->node; + s->groups.root = &newg->node; + } + + if (s->groups.rightmost == &g->node) + s->groups.rightmost = &newg->node; + + lzma_free(g, allocator); + + // NOTE: newg isn't leaked here because + // newg == (void *)&newg->node. + } + } + + // Add all the Streams from src to dest. Update the base offsets + // of each Stream from src. + const index_cat_info info = { + .uncompressed_size = dest->uncompressed_size, + .file_size = dest_file_size, + .stream_number_add = dest->streams.count, + .block_number_add = dest->record_count, + .streams = &dest->streams, + }; + index_cat_helper(&info, (index_stream *)(src->streams.root)); + + // Update info about all the combined Streams. + dest->uncompressed_size += src->uncompressed_size; + dest->total_size += src->total_size; + dest->record_count += src->record_count; + dest->index_list_size += src->index_list_size; + dest->checks = lzma_index_checks(dest) | src->checks; + + // There's nothing else left in src than the base structure. + lzma_free(src, allocator); + + return LZMA_OK; +} + + +/// Duplicate an index_stream. +static index_stream * +index_dup_stream(const index_stream *src, const lzma_allocator *allocator) +{ + // Catch a somewhat theoretical integer overflow. + if (src->record_count > PREALLOC_MAX) + return NULL; + + // Allocate and initialize a new Stream. + index_stream *dest = index_stream_init(src->node.compressed_base, + src->node.uncompressed_base, src->number, + src->block_number_base, allocator); + if (dest == NULL) + return NULL; + + // Copy the overall information. + dest->record_count = src->record_count; + dest->index_list_size = src->index_list_size; + dest->stream_flags = src->stream_flags; + dest->stream_padding = src->stream_padding; + + // Return if there are no groups to duplicate. + if (src->groups.leftmost == NULL) + return dest; + + // Allocate memory for the Records. We put all the Records into + // a single group. It's simplest and also tends to make + // lzma_index_locate() a little bit faster with very big Indexes. + index_group *destg = lzma_alloc(sizeof(index_group) + + src->record_count * sizeof(index_record), + allocator); + if (destg == NULL) { + index_stream_end(dest, allocator); + return NULL; + } + + // Initialize destg. + destg->node.uncompressed_base = 0; + destg->node.compressed_base = 0; + destg->number_base = 1; + destg->allocated = src->record_count; + destg->last = src->record_count - 1; + + // Go through all the groups in src and copy the Records into destg. + const index_group *srcg = (const index_group *)(src->groups.leftmost); + size_t i = 0; + do { + memcpy(destg->records + i, srcg->records, + (srcg->last + 1) * sizeof(index_record)); + i += srcg->last + 1; + srcg = index_tree_next(&srcg->node); + } while (srcg != NULL); + + assert(i == destg->allocated); + + // Add the group to the new Stream. + index_tree_append(&dest->groups, &destg->node); + + return dest; +} + + +extern LZMA_API(lzma_index *) +lzma_index_dup(const lzma_index *src, const lzma_allocator *allocator) +{ + // Allocate the base structure (no initial Stream). + lzma_index *dest = index_init_plain(allocator); + if (dest == NULL) + return NULL; + + // Copy the totals. + dest->uncompressed_size = src->uncompressed_size; + dest->total_size = src->total_size; + dest->record_count = src->record_count; + dest->index_list_size = src->index_list_size; + + // Copy the Streams and the groups in them. + const index_stream *srcstream + = (const index_stream *)(src->streams.leftmost); + do { + index_stream *deststream = index_dup_stream( + srcstream, allocator); + if (deststream == NULL) { + lzma_index_end(dest, allocator); + return NULL; + } + + index_tree_append(&dest->streams, &deststream->node); + + srcstream = index_tree_next(&srcstream->node); + } while (srcstream != NULL); + + return dest; +} + + +/// Indexing for lzma_index_iter.internal[] +enum { + ITER_INDEX, + ITER_STREAM, + ITER_GROUP, + ITER_RECORD, + ITER_METHOD, +}; + + +/// Values for lzma_index_iter.internal[ITER_METHOD].s +enum { + ITER_METHOD_NORMAL, + ITER_METHOD_NEXT, + ITER_METHOD_LEFTMOST, +}; + + +static void +iter_set_info(lzma_index_iter *iter) +{ + const lzma_index *i = iter->internal[ITER_INDEX].p; + const index_stream *stream = iter->internal[ITER_STREAM].p; + const index_group *group = iter->internal[ITER_GROUP].p; + const size_t record = iter->internal[ITER_RECORD].s; + + // lzma_index_iter.internal must not contain a pointer to the last + // group in the index, because that may be reallocated by + // lzma_index_cat(). + if (group == NULL) { + // There are no groups. + assert(stream->groups.root == NULL); + iter->internal[ITER_METHOD].s = ITER_METHOD_LEFTMOST; + + } else if (i->streams.rightmost != &stream->node + || stream->groups.rightmost != &group->node) { + // The group is not not the last group in the index. + iter->internal[ITER_METHOD].s = ITER_METHOD_NORMAL; + + } else if (stream->groups.leftmost != &group->node) { + // The group isn't the only group in the Stream, thus we + // know that it must have a parent group i.e. it's not + // the root node. + assert(stream->groups.root != &group->node); + assert(group->node.parent->right == &group->node); + iter->internal[ITER_METHOD].s = ITER_METHOD_NEXT; + iter->internal[ITER_GROUP].p = group->node.parent; + + } else { + // The Stream has only one group. + assert(stream->groups.root == &group->node); + assert(group->node.parent == NULL); + iter->internal[ITER_METHOD].s = ITER_METHOD_LEFTMOST; + iter->internal[ITER_GROUP].p = NULL; + } + + // NOTE: lzma_index_iter.stream.number is lzma_vli but we use uint32_t + // internally. + iter->stream.number = stream->number; + iter->stream.block_count = stream->record_count; + iter->stream.compressed_offset = stream->node.compressed_base; + iter->stream.uncompressed_offset = stream->node.uncompressed_base; + + // iter->stream.flags will be NULL if the Stream Flags haven't been + // set with lzma_index_stream_flags(). + iter->stream.flags = stream->stream_flags.version == UINT32_MAX + ? NULL : &stream->stream_flags; + iter->stream.padding = stream->stream_padding; + + if (stream->groups.rightmost == NULL) { + // Stream has no Blocks. + iter->stream.compressed_size = index_size(0, 0) + + 2 * LZMA_STREAM_HEADER_SIZE; + iter->stream.uncompressed_size = 0; + } else { + const index_group *g = (const index_group *)( + stream->groups.rightmost); + + // Stream Header + Stream Footer + Index + Blocks + iter->stream.compressed_size = 2 * LZMA_STREAM_HEADER_SIZE + + index_size(stream->record_count, + stream->index_list_size) + + vli_ceil4(g->records[g->last].unpadded_sum); + iter->stream.uncompressed_size + = g->records[g->last].uncompressed_sum; + } + + if (group != NULL) { + iter->block.number_in_stream = group->number_base + record; + iter->block.number_in_file = iter->block.number_in_stream + + stream->block_number_base; + + iter->block.compressed_stream_offset + = record == 0 ? group->node.compressed_base + : vli_ceil4(group->records[ + record - 1].unpadded_sum); + iter->block.uncompressed_stream_offset + = record == 0 ? group->node.uncompressed_base + : group->records[record - 1].uncompressed_sum; + + iter->block.uncompressed_size + = group->records[record].uncompressed_sum + - iter->block.uncompressed_stream_offset; + iter->block.unpadded_size + = group->records[record].unpadded_sum + - iter->block.compressed_stream_offset; + iter->block.total_size = vli_ceil4(iter->block.unpadded_size); + + iter->block.compressed_stream_offset + += LZMA_STREAM_HEADER_SIZE; + + iter->block.compressed_file_offset + = iter->block.compressed_stream_offset + + iter->stream.compressed_offset; + iter->block.uncompressed_file_offset + = iter->block.uncompressed_stream_offset + + iter->stream.uncompressed_offset; + } + + return; +} + + +extern LZMA_API(void) +lzma_index_iter_init(lzma_index_iter *iter, const lzma_index *i) +{ + iter->internal[ITER_INDEX].p = i; + lzma_index_iter_rewind(iter); + return; +} + + +extern LZMA_API(void) +lzma_index_iter_rewind(lzma_index_iter *iter) +{ + iter->internal[ITER_STREAM].p = NULL; + iter->internal[ITER_GROUP].p = NULL; + iter->internal[ITER_RECORD].s = 0; + iter->internal[ITER_METHOD].s = ITER_METHOD_NORMAL; + return; +} + + +extern LZMA_API(lzma_bool) +lzma_index_iter_next(lzma_index_iter *iter, lzma_index_iter_mode mode) +{ + // Catch unsupported mode values. + if ((unsigned int)(mode) > LZMA_INDEX_ITER_NONEMPTY_BLOCK) + return true; + + const lzma_index *i = iter->internal[ITER_INDEX].p; + const index_stream *stream = iter->internal[ITER_STREAM].p; + const index_group *group = NULL; + size_t record = iter->internal[ITER_RECORD].s; + + // If we are being asked for the next Stream, leave group to NULL + // so that the rest of the this function thinks that this Stream + // has no groups and will thus go to the next Stream. + if (mode != LZMA_INDEX_ITER_STREAM) { + // Get the pointer to the current group. See iter_set_inf() + // for explanation. + switch (iter->internal[ITER_METHOD].s) { + case ITER_METHOD_NORMAL: + group = iter->internal[ITER_GROUP].p; + break; + + case ITER_METHOD_NEXT: + group = index_tree_next(iter->internal[ITER_GROUP].p); + break; + + case ITER_METHOD_LEFTMOST: + group = (const index_group *)( + stream->groups.leftmost); + break; + } + } + +again: + if (stream == NULL) { + // We at the beginning of the lzma_index. + // Locate the first Stream. + stream = (const index_stream *)(i->streams.leftmost); + if (mode >= LZMA_INDEX_ITER_BLOCK) { + // Since we are being asked to return information + // about the first a Block, skip Streams that have + // no Blocks. + while (stream->groups.leftmost == NULL) { + stream = index_tree_next(&stream->node); + if (stream == NULL) + return true; + } + } + + // Start from the first Record in the Stream. + group = (const index_group *)(stream->groups.leftmost); + record = 0; + + } else if (group != NULL && record < group->last) { + // The next Record is in the same group. + ++record; + + } else { + // This group has no more Records or this Stream has + // no Blocks at all. + record = 0; + + // If group is not NULL, this Stream has at least one Block + // and thus at least one group. Find the next group. + if (group != NULL) + group = index_tree_next(&group->node); + + if (group == NULL) { + // This Stream has no more Records. Find the next + // Stream. If we are being asked to return information + // about a Block, we skip empty Streams. + do { + stream = index_tree_next(&stream->node); + if (stream == NULL) + return true; + } while (mode >= LZMA_INDEX_ITER_BLOCK + && stream->groups.leftmost == NULL); + + group = (const index_group *)( + stream->groups.leftmost); + } + } + + if (mode == LZMA_INDEX_ITER_NONEMPTY_BLOCK) { + // We need to look for the next Block again if this Block + // is empty. + if (record == 0) { + if (group->node.uncompressed_base + == group->records[0].uncompressed_sum) + goto again; + } else if (group->records[record - 1].uncompressed_sum + == group->records[record].uncompressed_sum) { + goto again; + } + } + + iter->internal[ITER_STREAM].p = stream; + iter->internal[ITER_GROUP].p = group; + iter->internal[ITER_RECORD].s = record; + + iter_set_info(iter); + + return false; +} + + +extern LZMA_API(lzma_bool) +lzma_index_iter_locate(lzma_index_iter *iter, lzma_vli target) +{ + const lzma_index *i = iter->internal[ITER_INDEX].p; + + // If the target is past the end of the file, return immediately. + if (i->uncompressed_size <= target) + return true; + + // Locate the Stream containing the target offset. + const index_stream *stream = index_tree_locate(&i->streams, target); + assert(stream != NULL); + target -= stream->node.uncompressed_base; + + // Locate the group containing the target offset. + const index_group *group = index_tree_locate(&stream->groups, target); + assert(group != NULL); + + // Use binary search to locate the exact Record. It is the first + // Record whose uncompressed_sum is greater than target. + // This is because we want the rightmost Record that fullfills the + // search criterion. It is possible that there are empty Blocks; + // we don't want to return them. + size_t left = 0; + size_t right = group->last; + + while (left < right) { + const size_t pos = left + (right - left) / 2; + if (group->records[pos].uncompressed_sum <= target) + left = pos + 1; + else + right = pos; + } + + iter->internal[ITER_STREAM].p = stream; + iter->internal[ITER_GROUP].p = group; + iter->internal[ITER_RECORD].s = left; + + iter_set_info(iter); + + return false; +}