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authorSrinivasarao P <spathi@codeaurora.org>2018-08-28 17:27:24 +0530
committerSrinivasarao P <spathi@codeaurora.org>2018-08-28 17:28:39 +0530
commitb87d31674ac9e8203f3a30b53f6a697bf5cf36b6 (patch)
tree6b9b8869b7d60d93b4c78b5ab2cd03b3f4a5a2e6 /lib/zstd/bitstream.h
parent40eed1f50062df731c0bf79af27c463b7d2003a1 (diff)
parent5e24b4e4d3724968a1c106e9dae091ef4dfc578e (diff)
Merge android-4.4.153 (5e24b4e) into msm-4.4
* refs/heads/tmp-5e24b4e Linux 4.4.153 ovl: warn instead of error if d_type is not supported ovl: Do d_type check only if work dir creation was successful ovl: Ensure upper filesystem supports d_type x86/mm: Fix use-after-free of ldt_struct x86/mm/pat: Fix L1TF stable backport for CPA ANDROID: x86_64_cuttlefish_defconfig: Enable lz4 compression for zram UPSTREAM: drivers/block/zram/zram_drv.c: fix bug storing backing_dev BACKPORT: zram: introduce zram memory tracking BACKPORT: zram: record accessed second BACKPORT: zram: mark incompressible page as ZRAM_HUGE UPSTREAM: zram: correct flag name of ZRAM_ACCESS UPSTREAM: zram: Delete gendisk before cleaning up the request queue UPSTREAM: drivers/block/zram/zram_drv.c: make zram_page_end_io() static BACKPORT: zram: set BDI_CAP_STABLE_WRITES once UPSTREAM: zram: fix null dereference of handle UPSTREAM: zram: add config and doc file for writeback feature BACKPORT: zram: read page from backing device BACKPORT: zram: write incompressible pages to backing device BACKPORT: zram: identify asynchronous IO's return value BACKPORT: zram: add free space management in backing device UPSTREAM: zram: add interface to specif backing device UPSTREAM: zram: rename zram_decompress_page to __zram_bvec_read UPSTREAM: zram: inline zram_compress UPSTREAM: zram: clean up duplicated codes in __zram_bvec_write Linux 4.4.152 reiserfs: fix broken xattr handling (heap corruption, bad retval) i2c: imx: Fix race condition in dma read PCI: pciehp: Fix use-after-free on unplug PCI: Skip MPS logic for Virtual Functions (VFs) PCI: hotplug: Don't leak pci_slot on registration failure parisc: Remove unnecessary barriers from spinlock.h bridge: Propagate vlan add failure to user packet: refine ring v3 block size test to hold one frame netfilter: conntrack: dccp: treat SYNC/SYNCACK as invalid if no prior state xfrm_user: prevent leaking 2 bytes of kernel memory parisc: Remove ordered stores from syscall.S ext4: fix spectre gadget in ext4_mb_regular_allocator() KVM: irqfd: fix race between EPOLLHUP and irq_bypass_register_consumer staging: android: ion: check for kref overflow tcp: identify cryptic messages as TCP seq # bugs net: qca_spi: Fix log level if probe fails net: qca_spi: Make sure the QCA7000 reset is triggered net: qca_spi: Avoid packet drop during initial sync net: usb: rtl8150: demote allmulti message to dev_dbg() net/ethernet/freescale/fman: fix cross-build error drm/nouveau/gem: off by one bugs in nouveau_gem_pushbuf_reloc_apply() tcp: remove DELAYED ACK events in DCTCP qlogic: check kstrtoul() for errors packet: reset network header if packet shorter than ll reserved space ixgbe: Be more careful when modifying MAC filters ARM: dts: am3517.dtsi: Disable reference to OMAP3 OTG controller ARM: 8780/1: ftrace: Only set kernel memory back to read-only after boot perf llvm-utils: Remove bashism from kernel include fetch script bnxt_en: Fix for system hang if request_irq fails drm/armada: fix colorkey mode property ieee802154: fakelb: switch from BUG_ON() to WARN_ON() on problem ieee802154: at86rf230: use __func__ macro for debug messages ieee802154: at86rf230: switch from BUG_ON() to WARN_ON() on problem ARM: pxa: irq: fix handling of ICMR registers in suspend/resume netfilter: x_tables: set module owner for icmp(6) matches smsc75xx: Add workaround for gigabit link up hardware errata. kasan: fix shadow_size calculation error in kasan_module_alloc tracing: Use __printf markup to silence compiler ARM: imx_v4_v5_defconfig: Select ULPI support ARM: imx_v6_v7_defconfig: Select ULPI support HID: wacom: Correct touch maximum XY of 2nd-gen Intuos m68k: fix "bad page state" oops on ColdFire boot bnx2x: Fix receiving tx-timeout in error or recovery state. drm/exynos: decon5433: Fix WINCONx reset value drm/exynos: decon5433: Fix per-plane global alpha for XRGB modes drm/exynos: gsc: Fix support for NV16/61, YUV420/YVU420 and YUV422 modes md/raid10: fix that replacement cannot complete recovery after reassemble dmaengine: k3dma: Off by one in k3_of_dma_simple_xlate() ARM: dts: da850: Fix interrups property for gpio selftests/x86/sigreturn/64: Fix spurious failures on AMD CPUs perf report powerpc: Fix crash if callchain is empty perf test session topology: Fix test on s390 usb: xhci: increase CRS timeout value ARM: dts: am437x: make edt-ft5x06 a wakeup source brcmfmac: stop watchdog before detach and free everything cxgb4: when disabling dcb set txq dcb priority to 0 Smack: Mark inode instant in smack_task_to_inode ipv6: mcast: fix unsolicited report interval after receiving querys locking/lockdep: Do not record IRQ state within lockdep code net: davinci_emac: match the mdio device against its compatible if possible ARC: Enable machine_desc->init_per_cpu for !CONFIG_SMP net: propagate dev_get_valid_name return code net: hamradio: use eth_broadcast_addr enic: initialize enic->rfs_h.lock in enic_probe qed: Add sanity check for SIMD fastpath handler. arm64: make secondary_start_kernel() notrace scsi: xen-scsifront: add error handling for xenbus_printf usb: gadget: dwc2: fix memory leak in gadget_init() usb: gadget: composite: fix delayed_status race condition when set_interface usb: dwc2: fix isoc split in transfer with no data ARM: dts: Cygnus: Fix I2C controller interrupt type selftests: sync: add config fragment for testing sync framework selftests: zram: return Kselftest Skip code for skipped tests selftests: user: return Kselftest Skip code for skipped tests selftests: static_keys: return Kselftest Skip code for skipped tests selftests: pstore: return Kselftest Skip code for skipped tests netfilter: ipv6: nf_defrag: reduce struct net memory waste ARC: Explicitly add -mmedium-calls to CFLAGS ANDROID: x86_64_cuttlefish_defconfig: Enable zram and zstd BACKPORT: crypto: zstd - Add zstd support UPSTREAM: zram: add zstd to the supported algorithms list UPSTREAM: lib: Add zstd modules UPSTREAM: lib: Add xxhash module UPSTREAM: zram: rework copy of compressor name in comp_algorithm_store() UPSTREAM: zram: constify attribute_group structures. UPSTREAM: zram: count same page write as page_stored UPSTREAM: zram: reduce load operation in page_same_filled UPSTREAM: zram: use zram_free_page instead of open-coded UPSTREAM: zram: introduce zram data accessor UPSTREAM: zram: remove zram_meta structure UPSTREAM: zram: use zram_slot_lock instead of raw bit_spin_lock op BACKPORT: zram: partial IO refactoring BACKPORT: zram: handle multiple pages attached bio's bvec UPSTREAM: zram: fix operator precedence to get offset BACKPORT: zram: extend zero pages to same element pages BACKPORT: zram: remove waitqueue for IO done UPSTREAM: zram: remove obsolete sysfs attrs UPSTREAM: zram: support BDI_CAP_STABLE_WRITES UPSTREAM: zram: revalidate disk under init_lock BACKPORT: mm: support anonymous stable page UPSTREAM: zram: use __GFP_MOVABLE for memory allocation UPSTREAM: zram: drop gfp_t from zcomp_strm_alloc() UPSTREAM: zram: add more compression algorithms UPSTREAM: zram: delete custom lzo/lz4 UPSTREAM: zram: cosmetic: cleanup documentation UPSTREAM: zram: use crypto api to check alg availability BACKPORT: zram: switch to crypto compress API UPSTREAM: zram: rename zstrm find-release functions UPSTREAM: zram: introduce per-device debug_stat sysfs node UPSTREAM: zram: remove max_comp_streams internals UPSTREAM: zram: user per-cpu compression streams BACKPORT: zsmalloc: require GFP in zs_malloc() UPSTREAM: zram/zcomp: do not zero out zcomp private pages UPSTREAM: zram: pass gfp from zcomp frontend to backend UPSTREAM: socket: close race condition between sock_close() and sockfs_setattr() ANDROID: Refresh x86_64_cuttlefish_defconfig Linux 4.4.151 isdn: Disable IIOCDBGVAR Bluetooth: avoid killing an already killed socket x86/mm: Simplify p[g4um]d_page() macros serial: 8250_dw: always set baud rate in dw8250_set_termios ACPI / PM: save NVS memory for ASUS 1025C laptop ACPI: save NVS memory for Lenovo G50-45 USB: option: add support for DW5821e USB: serial: sierra: fix potential deadlock at close ALSA: vxpocket: Fix invalid endian conversions ALSA: memalloc: Don't exceed over the requested size ALSA: hda: Correct Asrock B85M-ITX power_save blacklist entry ALSA: cs5535audio: Fix invalid endian conversion ALSA: virmidi: Fix too long output trigger loop ALSA: vx222: Fix invalid endian conversions ALSA: hda - Turn CX8200 into D3 as well upon reboot ALSA: hda - Sleep for 10ms after entering D3 on Conexant codecs net_sched: fix NULL pointer dereference when delete tcindex filter vsock: split dwork to avoid reinitializations net_sched: Fix missing res info when create new tc_index filter llc: use refcount_inc_not_zero() for llc_sap_find() l2tp: use sk_dst_check() to avoid race on sk->sk_dst_cache dccp: fix undefined behavior with 'cwnd' shift in ccid2_cwnd_restart() Conflicts: drivers/block/zram/zram_drv.c drivers/staging/android/ion/ion.c include/linux/swap.h mm/zsmalloc.c Change-Id: I1c437ac5133503a939d06d51ec778b65371df6d1 Signed-off-by: Srinivasarao P <spathi@codeaurora.org>
Diffstat (limited to 'lib/zstd/bitstream.h')
-rw-r--r--lib/zstd/bitstream.h374
1 files changed, 374 insertions, 0 deletions
diff --git a/lib/zstd/bitstream.h b/lib/zstd/bitstream.h
new file mode 100644
index 000000000000..a826b99e1d63
--- /dev/null
+++ b/lib/zstd/bitstream.h
@@ -0,0 +1,374 @@
+/*
+ * bitstream
+ * Part of FSE library
+ * header file (to include)
+ * Copyright (C) 2013-2016, Yann Collet.
+ *
+ * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation. This program is dual-licensed; you may select
+ * either version 2 of the GNU General Public License ("GPL") or BSD license
+ * ("BSD").
+ *
+ * You can contact the author at :
+ * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
+ */
+#ifndef BITSTREAM_H_MODULE
+#define BITSTREAM_H_MODULE
+
+/*
+* This API consists of small unitary functions, which must be inlined for best performance.
+* Since link-time-optimization is not available for all compilers,
+* these functions are defined into a .h to be included.
+*/
+
+/*-****************************************
+* Dependencies
+******************************************/
+#include "error_private.h" /* error codes and messages */
+#include "mem.h" /* unaligned access routines */
+
+/*=========================================
+* Target specific
+=========================================*/
+#define STREAM_ACCUMULATOR_MIN_32 25
+#define STREAM_ACCUMULATOR_MIN_64 57
+#define STREAM_ACCUMULATOR_MIN ((U32)(ZSTD_32bits() ? STREAM_ACCUMULATOR_MIN_32 : STREAM_ACCUMULATOR_MIN_64))
+
+/*-******************************************
+* bitStream encoding API (write forward)
+********************************************/
+/* bitStream can mix input from multiple sources.
+* A critical property of these streams is that they encode and decode in **reverse** direction.
+* So the first bit sequence you add will be the last to be read, like a LIFO stack.
+*/
+typedef struct {
+ size_t bitContainer;
+ int bitPos;
+ char *startPtr;
+ char *ptr;
+ char *endPtr;
+} BIT_CStream_t;
+
+ZSTD_STATIC size_t BIT_initCStream(BIT_CStream_t *bitC, void *dstBuffer, size_t dstCapacity);
+ZSTD_STATIC void BIT_addBits(BIT_CStream_t *bitC, size_t value, unsigned nbBits);
+ZSTD_STATIC void BIT_flushBits(BIT_CStream_t *bitC);
+ZSTD_STATIC size_t BIT_closeCStream(BIT_CStream_t *bitC);
+
+/* Start with initCStream, providing the size of buffer to write into.
+* bitStream will never write outside of this buffer.
+* `dstCapacity` must be >= sizeof(bitD->bitContainer), otherwise @return will be an error code.
+*
+* bits are first added to a local register.
+* Local register is size_t, hence 64-bits on 64-bits systems, or 32-bits on 32-bits systems.
+* Writing data into memory is an explicit operation, performed by the flushBits function.
+* Hence keep track how many bits are potentially stored into local register to avoid register overflow.
+* After a flushBits, a maximum of 7 bits might still be stored into local register.
+*
+* Avoid storing elements of more than 24 bits if you want compatibility with 32-bits bitstream readers.
+*
+* Last operation is to close the bitStream.
+* The function returns the final size of CStream in bytes.
+* If data couldn't fit into `dstBuffer`, it will return a 0 ( == not storable)
+*/
+
+/*-********************************************
+* bitStream decoding API (read backward)
+**********************************************/
+typedef struct {
+ size_t bitContainer;
+ unsigned bitsConsumed;
+ const char *ptr;
+ const char *start;
+} BIT_DStream_t;
+
+typedef enum {
+ BIT_DStream_unfinished = 0,
+ BIT_DStream_endOfBuffer = 1,
+ BIT_DStream_completed = 2,
+ BIT_DStream_overflow = 3
+} BIT_DStream_status; /* result of BIT_reloadDStream() */
+/* 1,2,4,8 would be better for bitmap combinations, but slows down performance a bit ... :( */
+
+ZSTD_STATIC size_t BIT_initDStream(BIT_DStream_t *bitD, const void *srcBuffer, size_t srcSize);
+ZSTD_STATIC size_t BIT_readBits(BIT_DStream_t *bitD, unsigned nbBits);
+ZSTD_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t *bitD);
+ZSTD_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t *bitD);
+
+/* Start by invoking BIT_initDStream().
+* A chunk of the bitStream is then stored into a local register.
+* Local register size is 64-bits on 64-bits systems, 32-bits on 32-bits systems (size_t).
+* You can then retrieve bitFields stored into the local register, **in reverse order**.
+* Local register is explicitly reloaded from memory by the BIT_reloadDStream() method.
+* A reload guarantee a minimum of ((8*sizeof(bitD->bitContainer))-7) bits when its result is BIT_DStream_unfinished.
+* Otherwise, it can be less than that, so proceed accordingly.
+* Checking if DStream has reached its end can be performed with BIT_endOfDStream().
+*/
+
+/*-****************************************
+* unsafe API
+******************************************/
+ZSTD_STATIC void BIT_addBitsFast(BIT_CStream_t *bitC, size_t value, unsigned nbBits);
+/* faster, but works only if value is "clean", meaning all high bits above nbBits are 0 */
+
+ZSTD_STATIC void BIT_flushBitsFast(BIT_CStream_t *bitC);
+/* unsafe version; does not check buffer overflow */
+
+ZSTD_STATIC size_t BIT_readBitsFast(BIT_DStream_t *bitD, unsigned nbBits);
+/* faster, but works only if nbBits >= 1 */
+
+/*-**************************************************************
+* Internal functions
+****************************************************************/
+ZSTD_STATIC unsigned BIT_highbit32(register U32 val) { return 31 - __builtin_clz(val); }
+
+/*===== Local Constants =====*/
+static const unsigned BIT_mask[] = {0, 1, 3, 7, 0xF, 0x1F, 0x3F, 0x7F, 0xFF,
+ 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF, 0x1FFFF,
+ 0x3FFFF, 0x7FFFF, 0xFFFFF, 0x1FFFFF, 0x3FFFFF, 0x7FFFFF, 0xFFFFFF, 0x1FFFFFF, 0x3FFFFFF}; /* up to 26 bits */
+
+/*-**************************************************************
+* bitStream encoding
+****************************************************************/
+/*! BIT_initCStream() :
+ * `dstCapacity` must be > sizeof(void*)
+ * @return : 0 if success,
+ otherwise an error code (can be tested using ERR_isError() ) */
+ZSTD_STATIC size_t BIT_initCStream(BIT_CStream_t *bitC, void *startPtr, size_t dstCapacity)
+{
+ bitC->bitContainer = 0;
+ bitC->bitPos = 0;
+ bitC->startPtr = (char *)startPtr;
+ bitC->ptr = bitC->startPtr;
+ bitC->endPtr = bitC->startPtr + dstCapacity - sizeof(bitC->ptr);
+ if (dstCapacity <= sizeof(bitC->ptr))
+ return ERROR(dstSize_tooSmall);
+ return 0;
+}
+
+/*! BIT_addBits() :
+ can add up to 26 bits into `bitC`.
+ Does not check for register overflow ! */
+ZSTD_STATIC void BIT_addBits(BIT_CStream_t *bitC, size_t value, unsigned nbBits)
+{
+ bitC->bitContainer |= (value & BIT_mask[nbBits]) << bitC->bitPos;
+ bitC->bitPos += nbBits;
+}
+
+/*! BIT_addBitsFast() :
+ * works only if `value` is _clean_, meaning all high bits above nbBits are 0 */
+ZSTD_STATIC void BIT_addBitsFast(BIT_CStream_t *bitC, size_t value, unsigned nbBits)
+{
+ bitC->bitContainer |= value << bitC->bitPos;
+ bitC->bitPos += nbBits;
+}
+
+/*! BIT_flushBitsFast() :
+ * unsafe version; does not check buffer overflow */
+ZSTD_STATIC void BIT_flushBitsFast(BIT_CStream_t *bitC)
+{
+ size_t const nbBytes = bitC->bitPos >> 3;
+ ZSTD_writeLEST(bitC->ptr, bitC->bitContainer);
+ bitC->ptr += nbBytes;
+ bitC->bitPos &= 7;
+ bitC->bitContainer >>= nbBytes * 8; /* if bitPos >= sizeof(bitContainer)*8 --> undefined behavior */
+}
+
+/*! BIT_flushBits() :
+ * safe version; check for buffer overflow, and prevents it.
+ * note : does not signal buffer overflow. This will be revealed later on using BIT_closeCStream() */
+ZSTD_STATIC void BIT_flushBits(BIT_CStream_t *bitC)
+{
+ size_t const nbBytes = bitC->bitPos >> 3;
+ ZSTD_writeLEST(bitC->ptr, bitC->bitContainer);
+ bitC->ptr += nbBytes;
+ if (bitC->ptr > bitC->endPtr)
+ bitC->ptr = bitC->endPtr;
+ bitC->bitPos &= 7;
+ bitC->bitContainer >>= nbBytes * 8; /* if bitPos >= sizeof(bitContainer)*8 --> undefined behavior */
+}
+
+/*! BIT_closeCStream() :
+ * @return : size of CStream, in bytes,
+ or 0 if it could not fit into dstBuffer */
+ZSTD_STATIC size_t BIT_closeCStream(BIT_CStream_t *bitC)
+{
+ BIT_addBitsFast(bitC, 1, 1); /* endMark */
+ BIT_flushBits(bitC);
+
+ if (bitC->ptr >= bitC->endPtr)
+ return 0; /* doesn't fit within authorized budget : cancel */
+
+ return (bitC->ptr - bitC->startPtr) + (bitC->bitPos > 0);
+}
+
+/*-********************************************************
+* bitStream decoding
+**********************************************************/
+/*! BIT_initDStream() :
+* Initialize a BIT_DStream_t.
+* `bitD` : a pointer to an already allocated BIT_DStream_t structure.
+* `srcSize` must be the *exact* size of the bitStream, in bytes.
+* @return : size of stream (== srcSize) or an errorCode if a problem is detected
+*/
+ZSTD_STATIC size_t BIT_initDStream(BIT_DStream_t *bitD, const void *srcBuffer, size_t srcSize)
+{
+ if (srcSize < 1) {
+ memset(bitD, 0, sizeof(*bitD));
+ return ERROR(srcSize_wrong);
+ }
+
+ if (srcSize >= sizeof(bitD->bitContainer)) { /* normal case */
+ bitD->start = (const char *)srcBuffer;
+ bitD->ptr = (const char *)srcBuffer + srcSize - sizeof(bitD->bitContainer);
+ bitD->bitContainer = ZSTD_readLEST(bitD->ptr);
+ {
+ BYTE const lastByte = ((const BYTE *)srcBuffer)[srcSize - 1];
+ bitD->bitsConsumed = lastByte ? 8 - BIT_highbit32(lastByte) : 0; /* ensures bitsConsumed is always set */
+ if (lastByte == 0)
+ return ERROR(GENERIC); /* endMark not present */
+ }
+ } else {
+ bitD->start = (const char *)srcBuffer;
+ bitD->ptr = bitD->start;
+ bitD->bitContainer = *(const BYTE *)(bitD->start);
+ switch (srcSize) {
+ case 7: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[6]) << (sizeof(bitD->bitContainer) * 8 - 16);
+ case 6: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[5]) << (sizeof(bitD->bitContainer) * 8 - 24);
+ case 5: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[4]) << (sizeof(bitD->bitContainer) * 8 - 32);
+ case 4: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[3]) << 24;
+ case 3: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[2]) << 16;
+ case 2: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[1]) << 8;
+ default:;
+ }
+ {
+ BYTE const lastByte = ((const BYTE *)srcBuffer)[srcSize - 1];
+ bitD->bitsConsumed = lastByte ? 8 - BIT_highbit32(lastByte) : 0;
+ if (lastByte == 0)
+ return ERROR(GENERIC); /* endMark not present */
+ }
+ bitD->bitsConsumed += (U32)(sizeof(bitD->bitContainer) - srcSize) * 8;
+ }
+
+ return srcSize;
+}
+
+ZSTD_STATIC size_t BIT_getUpperBits(size_t bitContainer, U32 const start) { return bitContainer >> start; }
+
+ZSTD_STATIC size_t BIT_getMiddleBits(size_t bitContainer, U32 const start, U32 const nbBits) { return (bitContainer >> start) & BIT_mask[nbBits]; }
+
+ZSTD_STATIC size_t BIT_getLowerBits(size_t bitContainer, U32 const nbBits) { return bitContainer & BIT_mask[nbBits]; }
+
+/*! BIT_lookBits() :
+ * Provides next n bits from local register.
+ * local register is not modified.
+ * On 32-bits, maxNbBits==24.
+ * On 64-bits, maxNbBits==56.
+ * @return : value extracted
+ */
+ZSTD_STATIC size_t BIT_lookBits(const BIT_DStream_t *bitD, U32 nbBits)
+{
+ U32 const bitMask = sizeof(bitD->bitContainer) * 8 - 1;
+ return ((bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> 1) >> ((bitMask - nbBits) & bitMask);
+}
+
+/*! BIT_lookBitsFast() :
+* unsafe version; only works only if nbBits >= 1 */
+ZSTD_STATIC size_t BIT_lookBitsFast(const BIT_DStream_t *bitD, U32 nbBits)
+{
+ U32 const bitMask = sizeof(bitD->bitContainer) * 8 - 1;
+ return (bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> (((bitMask + 1) - nbBits) & bitMask);
+}
+
+ZSTD_STATIC void BIT_skipBits(BIT_DStream_t *bitD, U32 nbBits) { bitD->bitsConsumed += nbBits; }
+
+/*! BIT_readBits() :
+ * Read (consume) next n bits from local register and update.
+ * Pay attention to not read more than nbBits contained into local register.
+ * @return : extracted value.
+ */
+ZSTD_STATIC size_t BIT_readBits(BIT_DStream_t *bitD, U32 nbBits)
+{
+ size_t const value = BIT_lookBits(bitD, nbBits);
+ BIT_skipBits(bitD, nbBits);
+ return value;
+}
+
+/*! BIT_readBitsFast() :
+* unsafe version; only works only if nbBits >= 1 */
+ZSTD_STATIC size_t BIT_readBitsFast(BIT_DStream_t *bitD, U32 nbBits)
+{
+ size_t const value = BIT_lookBitsFast(bitD, nbBits);
+ BIT_skipBits(bitD, nbBits);
+ return value;
+}
+
+/*! BIT_reloadDStream() :
+* Refill `bitD` from buffer previously set in BIT_initDStream() .
+* This function is safe, it guarantees it will not read beyond src buffer.
+* @return : status of `BIT_DStream_t` internal register.
+ if status == BIT_DStream_unfinished, internal register is filled with >= (sizeof(bitD->bitContainer)*8 - 7) bits */
+ZSTD_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t *bitD)
+{
+ if (bitD->bitsConsumed > (sizeof(bitD->bitContainer) * 8)) /* should not happen => corruption detected */
+ return BIT_DStream_overflow;
+
+ if (bitD->ptr >= bitD->start + sizeof(bitD->bitContainer)) {
+ bitD->ptr -= bitD->bitsConsumed >> 3;
+ bitD->bitsConsumed &= 7;
+ bitD->bitContainer = ZSTD_readLEST(bitD->ptr);
+ return BIT_DStream_unfinished;
+ }
+ if (bitD->ptr == bitD->start) {
+ if (bitD->bitsConsumed < sizeof(bitD->bitContainer) * 8)
+ return BIT_DStream_endOfBuffer;
+ return BIT_DStream_completed;
+ }
+ {
+ U32 nbBytes = bitD->bitsConsumed >> 3;
+ BIT_DStream_status result = BIT_DStream_unfinished;
+ if (bitD->ptr - nbBytes < bitD->start) {
+ nbBytes = (U32)(bitD->ptr - bitD->start); /* ptr > start */
+ result = BIT_DStream_endOfBuffer;
+ }
+ bitD->ptr -= nbBytes;
+ bitD->bitsConsumed -= nbBytes * 8;
+ bitD->bitContainer = ZSTD_readLEST(bitD->ptr); /* reminder : srcSize > sizeof(bitD) */
+ return result;
+ }
+}
+
+/*! BIT_endOfDStream() :
+* @return Tells if DStream has exactly reached its end (all bits consumed).
+*/
+ZSTD_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t *DStream)
+{
+ return ((DStream->ptr == DStream->start) && (DStream->bitsConsumed == sizeof(DStream->bitContainer) * 8));
+}
+
+#endif /* BITSTREAM_H_MODULE */