#ifndef ZSTD_CWKSP_H #define ZSTD_CWKSP_H /* * Copyright (c) Yann Collet, Facebook, Inc. * All rights reserved. * * This source code is licensed under both the BSD-style license (found in the * LICENSE file in the root directory of this source tree) and the GPLv2 (found * in the COPYING file in the root directory of this source tree). * You may select, at your option, one of the above-listed licenses. */ /*-************************************* * Dependencies ***************************************/ #include "../common/zstd_internal.h" #if defined (__cplusplus) extern "C" { #endif /*-************************************* * Constants ***************************************/ /* Since the workspace is effectively its own little malloc implementation / * arena, when we run under ASAN, we should similarly insert redzones between * each internal element of the workspace, so ASAN will catch overruns that * reach outside an object but that stay inside the workspace. * * This defines the size of that redzone. */ #ifndef ZSTD_CWKSP_ASAN_REDZONE_SIZE #define ZSTD_CWKSP_ASAN_REDZONE_SIZE 128 #endif /* Set our tables and aligneds to align by 64 bytes */ #define ZSTD_CWKSP_ALIGNMENT_BYTES 64 /*-************************************* * Structures ***************************************/ typedef enum { ZSTD_cwksp_alloc_objects, ZSTD_cwksp_alloc_buffers, ZSTD_cwksp_alloc_aligned } ZSTD_cwksp_alloc_phase_e; /** * Used to describe whether the workspace is statically allocated (and will not * necessarily ever be freed), or if it's dynamically allocated and we can * expect a well-formed caller to free this. */ typedef enum { ZSTD_cwksp_dynamic_alloc, ZSTD_cwksp_static_alloc } ZSTD_cwksp_static_alloc_e; /** * Zstd fits all its internal datastructures into a single continuous buffer, * so that it only needs to perform a single OS allocation (or so that a buffer * can be provided to it and it can perform no allocations at all). This buffer * is called the workspace. * * Several optimizations complicate that process of allocating memory ranges * from this workspace for each internal datastructure: * * - These different internal datastructures have different setup requirements: * * - The static objects need to be cleared once and can then be trivially * reused for each compression. * * - Various buffers don't need to be initialized at all--they are always * written into before they're read. * * - The matchstate tables have a unique requirement that they don't need * their memory to be totally cleared, but they do need the memory to have * some bound, i.e., a guarantee that all values in the memory they've been * allocated is less than some maximum value (which is the starting value * for the indices that they will then use for compression). When this * guarantee is provided to them, they can use the memory without any setup * work. When it can't, they have to clear the area. * * - These buffers also have different alignment requirements. * * - We would like to reuse the objects in the workspace for multiple * compressions without having to perform any expensive reallocation or * reinitialization work. * * - We would like to be able to efficiently reuse the workspace across * multiple compressions **even when the compression parameters change** and * we need to resize some of the objects (where possible). * * To attempt to manage this buffer, given these constraints, the ZSTD_cwksp * abstraction was created. It works as follows: * * Workspace Layout: * * [ ... workspace ... ] * [objects][tables ... ->] free space [<- ... aligned][<- ... buffers] * * The various objects that live in the workspace are divided into the * following categories, and are allocated separately: * * - Static objects: this is optionally the enclosing ZSTD_CCtx or ZSTD_CDict, * so that literally everything fits in a single buffer. Note: if present, * this must be the first object in the workspace, since ZSTD_customFree{CCtx, * CDict}() rely on a pointer comparison to see whether one or two frees are * required. * * - Fixed size objects: these are fixed-size, fixed-count objects that are * nonetheless "dynamically" allocated in the workspace so that we can * control how they're initialized separately from the broader ZSTD_CCtx. * Examples: * - Entropy Workspace * - 2 x ZSTD_compressedBlockState_t * - CDict dictionary contents * * - Tables: these are any of several different datastructures (hash tables, * chain tables, binary trees) that all respect a common format: they are * uint32_t arrays, all of whose values are between 0 and (nextSrc - base). * Their sizes depend on the cparams. These tables are 64-byte aligned. * * - Aligned: these buffers are used for various purposes that require 4 byte * alignment, but don't require any initialization before they're used. These * buffers are each aligned to 64 bytes. * * - Buffers: these buffers are used for various purposes that don't require * any alignment or initialization before they're used. This means they can * be moved around at no cost for a new compression. * * Allocating Memory: * * The various types of objects must be allocated in order, so they can be * correctly packed into the workspace buffer. That order is: * * 1. Objects * 2. Buffers * 3. Aligned/Tables * * Attempts to reserve objects of different types out of order will fail. */ typedef struct { void* workspace; void* workspaceEnd; void* objectEnd; void* tableEnd; void* tableValidEnd; void* allocStart; BYTE allocFailed; int workspaceOversizedDuration; ZSTD_cwksp_alloc_phase_e phase; ZSTD_cwksp_static_alloc_e isStatic; } ZSTD_cwksp; /*-************************************* * Functions ***************************************/ MEM_STATIC size_t ZSTD_cwksp_available_space(ZSTD_cwksp* ws); MEM_STATIC void ZSTD_cwksp_assert_internal_consistency(ZSTD_cwksp* ws) { (void)ws; assert(ws->workspace <= ws->objectEnd); assert(ws->objectEnd <= ws->tableEnd); assert(ws->objectEnd <= ws->tableValidEnd); assert(ws->tableEnd <= ws->allocStart); assert(ws->tableValidEnd <= ws->allocStart); assert(ws->allocStart <= ws->workspaceEnd); } /** * Align must be a power of 2. */ MEM_STATIC size_t ZSTD_cwksp_align(size_t size, size_t const align) { size_t const mask = align - 1; assert((align & mask) == 0); return (size + mask) & ~mask; } /** * Use this to determine how much space in the workspace we will consume to * allocate this object. (Normally it should be exactly the size of the object, * but under special conditions, like ASAN, where we pad each object, it might * be larger.) * * Since tables aren't currently redzoned, you don't need to call through this * to figure out how much space you need for the matchState tables. Everything * else is though. * * Do not use for sizing aligned buffers. Instead, use ZSTD_cwksp_aligned_alloc_size(). */ MEM_STATIC size_t ZSTD_cwksp_alloc_size(size_t size) { if (size == 0) return 0; #if ZSTD_ADDRESS_SANITIZER && !defined (ZSTD_ASAN_DONT_POISON_WORKSPACE) return size + 2 * ZSTD_CWKSP_ASAN_REDZONE_SIZE; #else return size; #endif } /** * Returns an adjusted alloc size that is the nearest larger multiple of 64 bytes. * Used to determine the number of bytes required for a given "aligned". */ MEM_STATIC size_t ZSTD_cwksp_aligned_alloc_size(size_t size) { return ZSTD_cwksp_alloc_size(ZSTD_cwksp_align(size, ZSTD_CWKSP_ALIGNMENT_BYTES)); } /** * Returns the amount of additional space the cwksp must allocate * for internal purposes (currently only alignment). */ MEM_STATIC size_t ZSTD_cwksp_slack_space_required(void) { /* For alignment, the wksp will always allocate an additional n_1=[1, 64] bytes * to align the beginning of tables section, as well as another n_2=[0, 63] bytes * to align the beginning of the aligned secion. * * n_1 + n_2 == 64 bytes if the cwksp is freshly allocated, due to tables and * aligneds being sized in multiples of 64 bytes. */ size_t const slackSpace = ZSTD_CWKSP_ALIGNMENT_BYTES; return slackSpace; } /** * Return the number of additional bytes required to align a pointer to the given number of bytes. * alignBytes must be a power of two. */ MEM_STATIC size_t ZSTD_cwksp_bytes_to_align_ptr(void* ptr, const size_t alignBytes) { size_t const alignBytesMask = alignBytes - 1; size_t const bytes = (alignBytes - ((size_t)ptr & (alignBytesMask))) & alignBytesMask; assert((alignBytes & alignBytesMask) == 0); assert(bytes != ZSTD_CWKSP_ALIGNMENT_BYTES); return bytes; } /** * Internal function. Do not use directly. * Reserves the given number of bytes within the aligned/buffer segment of the wksp, which * counts from the end of the wksp. (as opposed to the object/table segment) * * Returns a pointer to the beginning of that space. */ MEM_STATIC void* ZSTD_cwksp_reserve_internal_buffer_space(ZSTD_cwksp* ws, size_t const bytes) { void* const alloc = (BYTE*)ws->allocStart - bytes; void* const bottom = ws->tableEnd; DEBUGLOG(5, "cwksp: reserving %p %zd bytes, %zd bytes remaining", alloc, bytes, ZSTD_cwksp_available_space(ws) - bytes); ZSTD_cwksp_assert_internal_consistency(ws); assert(alloc >= bottom); if (alloc < bottom) { DEBUGLOG(4, "cwksp: alloc failed!"); ws->allocFailed = 1; return NULL; } if (alloc < ws->tableValidEnd) { ws->tableValidEnd = alloc; } ws->allocStart = alloc; return alloc; } /** * Moves the cwksp to the next phase, and does any necessary allocations. * Returns a 0 on success, or zstd error */ MEM_STATIC size_t ZSTD_cwksp_internal_advance_phase( ZSTD_cwksp* ws, ZSTD_cwksp_alloc_phase_e phase) { assert(phase >= ws->phase); if (phase > ws->phase) { /* Going from allocating objects to allocating buffers */ if (ws->phase < ZSTD_cwksp_alloc_buffers && phase >= ZSTD_cwksp_alloc_buffers) { ws->tableValidEnd = ws->objectEnd; } /* Going from allocating buffers to allocating aligneds/tables */ if (ws->phase < ZSTD_cwksp_alloc_aligned && phase >= ZSTD_cwksp_alloc_aligned) { { /* Align the start of the "aligned" to 64 bytes. Use [1, 64] bytes. */ size_t const bytesToAlign = ZSTD_CWKSP_ALIGNMENT_BYTES - ZSTD_cwksp_bytes_to_align_ptr(ws->allocStart, ZSTD_CWKSP_ALIGNMENT_BYTES); DEBUGLOG(5, "reserving aligned alignment addtl space: %zu", bytesToAlign); ZSTD_STATIC_ASSERT((ZSTD_CWKSP_ALIGNMENT_BYTES & (ZSTD_CWKSP_ALIGNMENT_BYTES - 1)) == 0); /* power of 2 */ RETURN_ERROR_IF(!ZSTD_cwksp_reserve_internal_buffer_space(ws, bytesToAlign), memory_allocation, "aligned phase - alignment initial allocation failed!"); } { /* Align the start of the tables to 64 bytes. Use [0, 63] bytes */ void* const alloc = ws->objectEnd; size_t const bytesToAlign = ZSTD_cwksp_bytes_to_align_ptr(alloc, ZSTD_CWKSP_ALIGNMENT_BYTES); void* const end = (BYTE*)alloc + bytesToAlign; DEBUGLOG(5, "reserving table alignment addtl space: %zu", bytesToAlign); RETURN_ERROR_IF(end > ws->workspaceEnd, memory_allocation, "table phase - alignment initial allocation failed!"); ws->objectEnd = end; ws->tableEnd = end; ws->tableValidEnd = end; } } ws->phase = phase; ZSTD_cwksp_assert_internal_consistency(ws); } return 0; } /** * Returns whether this object/buffer/etc was allocated in this workspace. */ MEM_STATIC int ZSTD_cwksp_owns_buffer(const ZSTD_cwksp* ws, const void* ptr) { return (ptr != NULL) && (ws->workspace <= ptr) && (ptr <= ws->workspaceEnd); } /** * Internal function. Do not use directly. */ MEM_STATIC void* ZSTD_cwksp_reserve_internal( ZSTD_cwksp* ws, size_t bytes, ZSTD_cwksp_alloc_phase_e phase) { void* alloc; if (ZSTD_isError(ZSTD_cwksp_internal_advance_phase(ws, phase)) || bytes == 0) { return NULL; } #if ZSTD_ADDRESS_SANITIZER && !defined (ZSTD_ASAN_DONT_POISON_WORKSPACE) /* over-reserve space */ bytes += 2 * ZSTD_CWKSP_ASAN_REDZONE_SIZE; #endif alloc = ZSTD_cwksp_reserve_internal_buffer_space(ws, bytes); #if ZSTD_ADDRESS_SANITIZER && !defined (ZSTD_ASAN_DONT_POISON_WORKSPACE) /* Move alloc so there's ZSTD_CWKSP_ASAN_REDZONE_SIZE unused space on * either size. */ if (alloc) { alloc = (BYTE *)alloc + ZSTD_CWKSP_ASAN_REDZONE_SIZE; if (ws->isStatic == ZSTD_cwksp_dynamic_alloc) { __asan_unpoison_memory_region(alloc, bytes); } } #endif return alloc; } /** * Reserves and returns unaligned memory. */ MEM_STATIC BYTE* ZSTD_cwksp_reserve_buffer(ZSTD_cwksp* ws, size_t bytes) { return (BYTE*)ZSTD_cwksp_reserve_internal(ws, bytes, ZSTD_cwksp_alloc_buffers); } /** * Reserves and returns memory sized on and aligned on ZSTD_CWKSP_ALIGNMENT_BYTES (64 bytes). */ MEM_STATIC void* ZSTD_cwksp_reserve_aligned(ZSTD_cwksp* ws, size_t bytes) { void* ptr = ZSTD_cwksp_reserve_internal(ws, ZSTD_cwksp_align(bytes, ZSTD_CWKSP_ALIGNMENT_BYTES), ZSTD_cwksp_alloc_aligned); assert(((size_t)ptr & (ZSTD_CWKSP_ALIGNMENT_BYTES-1))== 0); return ptr; } /** * Aligned on 64 bytes. These buffers have the special property that * their values remain constrained, allowing us to re-use them without * memset()-ing them. */ MEM_STATIC void* ZSTD_cwksp_reserve_table(ZSTD_cwksp* ws, size_t bytes) { const ZSTD_cwksp_alloc_phase_e phase = ZSTD_cwksp_alloc_aligned; void* alloc; void* end; void* top; if (ZSTD_isError(ZSTD_cwksp_internal_advance_phase(ws, phase))) { return NULL; } alloc = ws->tableEnd; end = (BYTE *)alloc + bytes; top = ws->allocStart; DEBUGLOG(5, "cwksp: reserving %p table %zd bytes, %zd bytes remaining", alloc, bytes, ZSTD_cwksp_available_space(ws) - bytes); assert((bytes & (sizeof(U32)-1)) == 0); ZSTD_cwksp_assert_internal_consistency(ws); assert(end <= top); if (end > top) { DEBUGLOG(4, "cwksp: table alloc failed!"); ws->allocFailed = 1; return NULL; } ws->tableEnd = end; #if ZSTD_ADDRESS_SANITIZER && !defined (ZSTD_ASAN_DONT_POISON_WORKSPACE) if (ws->isStatic == ZSTD_cwksp_dynamic_alloc) { __asan_unpoison_memory_region(alloc, bytes); } #endif assert((bytes & (ZSTD_CWKSP_ALIGNMENT_BYTES-1)) == 0); assert(((size_t)alloc & (ZSTD_CWKSP_ALIGNMENT_BYTES-1))== 0); return alloc; } /** * Aligned on sizeof(void*). */ MEM_STATIC void* ZSTD_cwksp_reserve_object(ZSTD_cwksp* ws, size_t bytes) { size_t roundedBytes = ZSTD_cwksp_align(bytes, sizeof(void*)); void* alloc = ws->objectEnd; void* end = (BYTE*)alloc + roundedBytes; #if ZSTD_ADDRESS_SANITIZER && !defined (ZSTD_ASAN_DONT_POISON_WORKSPACE) /* over-reserve space */ end = (BYTE *)end + 2 * ZSTD_CWKSP_ASAN_REDZONE_SIZE; #endif DEBUGLOG(5, "cwksp: reserving %p object %zd bytes (rounded to %zd), %zd bytes remaining", alloc, bytes, roundedBytes, ZSTD_cwksp_available_space(ws) - roundedBytes); assert(((size_t)alloc & (sizeof(void*)-1)) == 0); assert((bytes & (sizeof(void*)-1)) == 0); ZSTD_cwksp_assert_internal_consistency(ws); /* we must be in the first phase, no advance is possible */ if (ws->phase != ZSTD_cwksp_alloc_objects || end > ws->workspaceEnd) { DEBUGLOG(4, "cwksp: object alloc failed!"); ws->allocFailed = 1; return NULL; } ws->objectEnd = end; ws->tableEnd = end; ws->tableValidEnd = end; #if ZSTD_ADDRESS_SANITIZER && !defined (ZSTD_ASAN_DONT_POISON_WORKSPACE) /* Move alloc so there's ZSTD_CWKSP_ASAN_REDZONE_SIZE unused space on * either size. */ alloc = (BYTE *)alloc + ZSTD_CWKSP_ASAN_REDZONE_SIZE; if (ws->isStatic == ZSTD_cwksp_dynamic_alloc) { __asan_unpoison_memory_region(alloc, bytes); } #endif return alloc; } MEM_STATIC void ZSTD_cwksp_mark_tables_dirty(ZSTD_cwksp* ws) { DEBUGLOG(4, "cwksp: ZSTD_cwksp_mark_tables_dirty"); #if ZSTD_MEMORY_SANITIZER && !defined (ZSTD_MSAN_DONT_POISON_WORKSPACE) /* To validate that the table re-use logic is sound, and that we don't * access table space that we haven't cleaned, we re-"poison" the table * space every time we mark it dirty. */ { size_t size = (BYTE*)ws->tableValidEnd - (BYTE*)ws->objectEnd; assert(__msan_test_shadow(ws->objectEnd, size) == -1); __msan_poison(ws->objectEnd, size); } #endif assert(ws->tableValidEnd >= ws->objectEnd); assert(ws->tableValidEnd <= ws->allocStart); ws->tableValidEnd = ws->objectEnd; ZSTD_cwksp_assert_internal_consistency(ws); } MEM_STATIC void ZSTD_cwksp_mark_tables_clean(ZSTD_cwksp* ws) { DEBUGLOG(4, "cwksp: ZSTD_cwksp_mark_tables_clean"); assert(ws->tableValidEnd >= ws->objectEnd); assert(ws->tableValidEnd <= ws->allocStart); if (ws->tableValidEnd < ws->tableEnd) { ws->tableValidEnd = ws->tableEnd; } ZSTD_cwksp_assert_internal_consistency(ws); } /** * Zero the part of the allocated tables not already marked clean. */ MEM_STATIC void ZSTD_cwksp_clean_tables(ZSTD_cwksp* ws) { DEBUGLOG(4, "cwksp: ZSTD_cwksp_clean_tables"); assert(ws->tableValidEnd >= ws->objectEnd); assert(ws->tableValidEnd <= ws->allocStart); if (ws->tableValidEnd < ws->tableEnd) { ZSTD_memset(ws->tableValidEnd, 0, (BYTE*)ws->tableEnd - (BYTE*)ws->tableValidEnd); } ZSTD_cwksp_mark_tables_clean(ws); } /** * Invalidates table allocations. * All other allocations remain valid. */ MEM_STATIC void ZSTD_cwksp_clear_tables(ZSTD_cwksp* ws) { DEBUGLOG(4, "cwksp: clearing tables!"); #if ZSTD_ADDRESS_SANITIZER && !defined (ZSTD_ASAN_DONT_POISON_WORKSPACE) /* We don't do this when the workspace is statically allocated, because * when that is the case, we have no capability to hook into the end of the * workspace's lifecycle to unpoison the memory. */ if (ws->isStatic == ZSTD_cwksp_dynamic_alloc) { size_t size = (BYTE*)ws->tableValidEnd - (BYTE*)ws->objectEnd; __asan_poison_memory_region(ws->objectEnd, size); } #endif ws->tableEnd = ws->objectEnd; ZSTD_cwksp_assert_internal_consistency(ws); } /** * Invalidates all buffer, aligned, and table allocations. * Object allocations remain valid. */ MEM_STATIC void ZSTD_cwksp_clear(ZSTD_cwksp* ws) { DEBUGLOG(4, "cwksp: clearing!"); #if ZSTD_MEMORY_SANITIZER && !defined (ZSTD_MSAN_DONT_POISON_WORKSPACE) /* To validate that the context re-use logic is sound, and that we don't * access stuff that this compression hasn't initialized, we re-"poison" * the workspace (or at least the non-static, non-table parts of it) * every time we start a new compression. */ { size_t size = (BYTE*)ws->workspaceEnd - (BYTE*)ws->tableValidEnd; __msan_poison(ws->tableValidEnd, size); } #endif #if ZSTD_ADDRESS_SANITIZER && !defined (ZSTD_ASAN_DONT_POISON_WORKSPACE) /* We don't do this when the workspace is statically allocated, because * when that is the case, we have no capability to hook into the end of the * workspace's lifecycle to unpoison the memory. */ if (ws->isStatic == ZSTD_cwksp_dynamic_alloc) { size_t size = (BYTE*)ws->workspaceEnd - (BYTE*)ws->objectEnd; __asan_poison_memory_region(ws->objectEnd, size); } #endif ws->tableEnd = ws->objectEnd; ws->allocStart = ws->workspaceEnd; ws->allocFailed = 0; if (ws->phase > ZSTD_cwksp_alloc_buffers) { ws->phase = ZSTD_cwksp_alloc_buffers; } ZSTD_cwksp_assert_internal_consistency(ws); } /** * The provided workspace takes ownership of the buffer [start, start+size). * Any existing values in the workspace are ignored (the previously managed * buffer, if present, must be separately freed). */ MEM_STATIC void ZSTD_cwksp_init(ZSTD_cwksp* ws, void* start, size_t size, ZSTD_cwksp_static_alloc_e isStatic) { DEBUGLOG(4, "cwksp: init'ing workspace with %zd bytes", size); assert(((size_t)start & (sizeof(void*)-1)) == 0); /* ensure correct alignment */ ws->workspace = start; ws->workspaceEnd = (BYTE*)start + size; ws->objectEnd = ws->workspace; ws->tableValidEnd = ws->objectEnd; ws->phase = ZSTD_cwksp_alloc_objects; ws->isStatic = isStatic; ZSTD_cwksp_clear(ws); ws->workspaceOversizedDuration = 0; ZSTD_cwksp_assert_internal_consistency(ws); } MEM_STATIC size_t ZSTD_cwksp_create(ZSTD_cwksp* ws, size_t size, ZSTD_customMem customMem) { void* workspace = ZSTD_customMalloc(size, customMem); DEBUGLOG(4, "cwksp: creating new workspace with %zd bytes", size); RETURN_ERROR_IF(workspace == NULL, memory_allocation, "NULL pointer!"); ZSTD_cwksp_init(ws, workspace, size, ZSTD_cwksp_dynamic_alloc); return 0; } MEM_STATIC void ZSTD_cwksp_free(ZSTD_cwksp* ws, ZSTD_customMem customMem) { void *ptr = ws->workspace; DEBUGLOG(4, "cwksp: freeing workspace"); ZSTD_memset(ws, 0, sizeof(ZSTD_cwksp)); ZSTD_customFree(ptr, customMem); } /** * Moves the management of a workspace from one cwksp to another. The src cwksp * is left in an invalid state (src must be re-init()'ed before it's used again). */ MEM_STATIC void ZSTD_cwksp_move(ZSTD_cwksp* dst, ZSTD_cwksp* src) { *dst = *src; ZSTD_memset(src, 0, sizeof(ZSTD_cwksp)); } MEM_STATIC size_t ZSTD_cwksp_sizeof(const ZSTD_cwksp* ws) { return (size_t)((BYTE*)ws->workspaceEnd - (BYTE*)ws->workspace); } MEM_STATIC size_t ZSTD_cwksp_used(const ZSTD_cwksp* ws) { return (size_t)((BYTE*)ws->tableEnd - (BYTE*)ws->workspace) + (size_t)((BYTE*)ws->workspaceEnd - (BYTE*)ws->allocStart); } MEM_STATIC int ZSTD_cwksp_reserve_failed(const ZSTD_cwksp* ws) { return ws->allocFailed; } /*-************************************* * Functions Checking Free Space ***************************************/ /* ZSTD_alignmentSpaceWithinBounds() : * Returns if the estimated space needed for a wksp is within an acceptable limit of the * actual amount of space used. */ MEM_STATIC int ZSTD_cwksp_estimated_space_within_bounds(const ZSTD_cwksp* const ws, size_t const estimatedSpace, int resizedWorkspace) { if (resizedWorkspace) { /* Resized/newly allocated wksp should have exact bounds */ return ZSTD_cwksp_used(ws) == estimatedSpace; } else { /* Due to alignment, when reusing a workspace, we can actually consume 63 fewer or more bytes * than estimatedSpace. See the comments in zstd_cwksp.h for details. */ return (ZSTD_cwksp_used(ws) >= estimatedSpace - 63) && (ZSTD_cwksp_used(ws) <= estimatedSpace + 63); } } MEM_STATIC size_t ZSTD_cwksp_available_space(ZSTD_cwksp* ws) { return (size_t)((BYTE*)ws->allocStart - (BYTE*)ws->tableEnd); } MEM_STATIC int ZSTD_cwksp_check_available(ZSTD_cwksp* ws, size_t additionalNeededSpace) { return ZSTD_cwksp_available_space(ws) >= additionalNeededSpace; } MEM_STATIC int ZSTD_cwksp_check_too_large(ZSTD_cwksp* ws, size_t additionalNeededSpace) { return ZSTD_cwksp_check_available( ws, additionalNeededSpace * ZSTD_WORKSPACETOOLARGE_FACTOR); } MEM_STATIC int ZSTD_cwksp_check_wasteful(ZSTD_cwksp* ws, size_t additionalNeededSpace) { return ZSTD_cwksp_check_too_large(ws, additionalNeededSpace) && ws->workspaceOversizedDuration > ZSTD_WORKSPACETOOLARGE_MAXDURATION; } MEM_STATIC void ZSTD_cwksp_bump_oversized_duration( ZSTD_cwksp* ws, size_t additionalNeededSpace) { if (ZSTD_cwksp_check_too_large(ws, additionalNeededSpace)) { ws->workspaceOversizedDuration++; } else { ws->workspaceOversizedDuration = 0; } } #if defined (__cplusplus) } #endif #endif /* ZSTD_CWKSP_H */