From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- lib/zstd/compress/zstd_cwksp.h | 482 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 482 insertions(+) create mode 100644 lib/zstd/compress/zstd_cwksp.h (limited to 'lib/zstd/compress/zstd_cwksp.h') diff --git a/lib/zstd/compress/zstd_cwksp.h b/lib/zstd/compress/zstd_cwksp.h new file mode 100644 index 000000000..98e359adf --- /dev/null +++ b/lib/zstd/compress/zstd_cwksp.h @@ -0,0 +1,482 @@ +/* + * 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. + */ + +#ifndef ZSTD_CWKSP_H +#define ZSTD_CWKSP_H + +/*-************************************* +* Dependencies +***************************************/ +#include "../common/zstd_internal.h" + + +/*-************************************* +* 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 + +/*-************************************* +* 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. + * + * - Aligned: these buffers are used for various purposes that require 4 byte + * alignment, but don't require any initialization before they're used. + * + * - 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 + * 4. 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. + */ +MEM_STATIC size_t ZSTD_cwksp_alloc_size(size_t size) { + if (size == 0) + return 0; + return size; +} + +MEM_STATIC void ZSTD_cwksp_internal_advance_phase( + ZSTD_cwksp* ws, ZSTD_cwksp_alloc_phase_e phase) { + assert(phase >= ws->phase); + if (phase > ws->phase) { + if (ws->phase < ZSTD_cwksp_alloc_buffers && + phase >= ZSTD_cwksp_alloc_buffers) { + ws->tableValidEnd = ws->objectEnd; + } + if (ws->phase < ZSTD_cwksp_alloc_aligned && + phase >= ZSTD_cwksp_alloc_aligned) { + /* If unaligned allocations down from a too-large top have left us + * unaligned, we need to realign our alloc ptr. Technically, this + * can consume space that is unaccounted for in the neededSpace + * calculation. However, I believe this can only happen when the + * workspace is too large, and specifically when it is too large + * by a larger margin than the space that will be consumed. */ + /* TODO: cleaner, compiler warning friendly way to do this??? */ + ws->allocStart = (BYTE*)ws->allocStart - ((size_t)ws->allocStart & (sizeof(U32)-1)); + if (ws->allocStart < ws->tableValidEnd) { + ws->tableValidEnd = ws->allocStart; + } + } + ws->phase = phase; + } +} + +/* + * 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; + void* bottom = ws->tableEnd; + ZSTD_cwksp_internal_advance_phase(ws, phase); + alloc = (BYTE *)ws->allocStart - bytes; + + if (bytes == 0) + return NULL; + + + 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; +} + +/* + * 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 sizeof(unsigned). + */ +MEM_STATIC void* ZSTD_cwksp_reserve_aligned(ZSTD_cwksp* ws, size_t bytes) { + assert((bytes & (sizeof(U32)-1)) == 0); + return ZSTD_cwksp_reserve_internal(ws, ZSTD_cwksp_align(bytes, sizeof(U32)), ZSTD_cwksp_alloc_aligned); +} + +/* + * Aligned on sizeof(unsigned). 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 = ws->tableEnd; + void* end = (BYTE *)alloc + bytes; + void* 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_internal_advance_phase(ws, phase); + 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; + + + 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; + + + 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; + + + return alloc; +} + +MEM_STATIC void ZSTD_cwksp_mark_tables_dirty(ZSTD_cwksp* ws) { + DEBUGLOG(4, "cwksp: ZSTD_cwksp_mark_tables_dirty"); + + + 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!"); + + + 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!"); + + + + 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 +***************************************/ + +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; + } +} + + +#endif /* ZSTD_CWKSP_H */ -- cgit v1.2.3