diff mupdf-source/thirdparty/brotli/c/enc/command.h @ 2:b50eed0cc0ef upstream

ADD: MuPDF v1.26.7: the MuPDF source as downloaded by a default build of PyMuPDF 1.26.4. The directory name has changed: no version number in the expanded directory now.
author Franz Glasner <fzglas.hg@dom66.de>
date Mon, 15 Sep 2025 11:43:07 +0200
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/brotli/c/enc/command.h	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,191 @@
+/* Copyright 2013 Google Inc. All Rights Reserved.
+
+   Distributed under MIT license.
+   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
+*/
+
+/* This class models a sequence of literals and a backward reference copy. */
+
+#ifndef BROTLI_ENC_COMMAND_H_
+#define BROTLI_ENC_COMMAND_H_
+
+#include <brotli/types.h>
+
+#include "../common/constants.h"
+#include "../common/platform.h"
+#include "fast_log.h"
+#include "params.h"
+#include "prefix.h"
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+BROTLI_INTERNAL extern const uint32_t
+    kBrotliInsBase[BROTLI_NUM_INS_COPY_CODES];
+BROTLI_INTERNAL extern const uint32_t
+    kBrotliInsExtra[BROTLI_NUM_INS_COPY_CODES];
+BROTLI_INTERNAL extern const uint32_t
+    kBrotliCopyBase[BROTLI_NUM_INS_COPY_CODES];
+BROTLI_INTERNAL extern const uint32_t
+    kBrotliCopyExtra[BROTLI_NUM_INS_COPY_CODES];
+
+static BROTLI_INLINE uint16_t GetInsertLengthCode(size_t insertlen) {
+  if (insertlen < 6) {
+    return (uint16_t)insertlen;
+  } else if (insertlen < 130) {
+    uint32_t nbits = Log2FloorNonZero(insertlen - 2) - 1u;
+    return (uint16_t)((nbits << 1) + ((insertlen - 2) >> nbits) + 2);
+  } else if (insertlen < 2114) {
+    return (uint16_t)(Log2FloorNonZero(insertlen - 66) + 10);
+  } else if (insertlen < 6210) {
+    return 21u;
+  } else if (insertlen < 22594) {
+    return 22u;
+  } else {
+    return 23u;
+  }
+}
+
+static BROTLI_INLINE uint16_t GetCopyLengthCode(size_t copylen) {
+  if (copylen < 10) {
+    return (uint16_t)(copylen - 2);
+  } else if (copylen < 134) {
+    uint32_t nbits = Log2FloorNonZero(copylen - 6) - 1u;
+    return (uint16_t)((nbits << 1) + ((copylen - 6) >> nbits) + 4);
+  } else if (copylen < 2118) {
+    return (uint16_t)(Log2FloorNonZero(copylen - 70) + 12);
+  } else {
+    return 23u;
+  }
+}
+
+static BROTLI_INLINE uint16_t CombineLengthCodes(
+    uint16_t inscode, uint16_t copycode, BROTLI_BOOL use_last_distance) {
+  uint16_t bits64 =
+      (uint16_t)((copycode & 0x7u) | ((inscode & 0x7u) << 3u));
+  if (use_last_distance && inscode < 8u && copycode < 16u) {
+    return (copycode < 8u) ? bits64 : (bits64 | 64u);
+  } else {
+    /* Specification: 5 Encoding of ... (last table) */
+    /* offset = 2 * index, where index is in range [0..8] */
+    uint32_t offset = 2u * ((copycode >> 3u) + 3u * (inscode >> 3u));
+    /* All values in specification are K * 64,
+       where   K = [2, 3, 6, 4, 5, 8, 7, 9, 10],
+           i + 1 = [1, 2, 3, 4, 5, 6, 7, 8,  9],
+       K - i - 1 = [1, 1, 3, 0, 0, 2, 0, 1,  2] = D.
+       All values in D require only 2 bits to encode.
+       Magic constant is shifted 6 bits left, to avoid final multiplication. */
+    offset = (offset << 5u) + 0x40u + ((0x520D40u >> offset) & 0xC0u);
+    return (uint16_t)(offset | bits64);
+  }
+}
+
+static BROTLI_INLINE void GetLengthCode(size_t insertlen, size_t copylen,
+                                        BROTLI_BOOL use_last_distance,
+                                        uint16_t* code) {
+  uint16_t inscode = GetInsertLengthCode(insertlen);
+  uint16_t copycode = GetCopyLengthCode(copylen);
+  *code = CombineLengthCodes(inscode, copycode, use_last_distance);
+}
+
+static BROTLI_INLINE uint32_t GetInsertBase(uint16_t inscode) {
+  return kBrotliInsBase[inscode];
+}
+
+static BROTLI_INLINE uint32_t GetInsertExtra(uint16_t inscode) {
+  return kBrotliInsExtra[inscode];
+}
+
+static BROTLI_INLINE uint32_t GetCopyBase(uint16_t copycode) {
+  return kBrotliCopyBase[copycode];
+}
+
+static BROTLI_INLINE uint32_t GetCopyExtra(uint16_t copycode) {
+  return kBrotliCopyExtra[copycode];
+}
+
+typedef struct Command {
+  uint32_t insert_len_;
+  /* Stores copy_len in low 25 bits and copy_code - copy_len in high 7 bit. */
+  uint32_t copy_len_;
+  /* Stores distance extra bits. */
+  uint32_t dist_extra_;
+  uint16_t cmd_prefix_;
+  /* Stores distance code in low 10 bits
+     and number of extra bits in high 6 bits. */
+  uint16_t dist_prefix_;
+} Command;
+
+/* distance_code is e.g. 0 for same-as-last short code, or 16 for offset 1. */
+static BROTLI_INLINE void InitCommand(Command* self,
+    const BrotliDistanceParams* dist, size_t insertlen,
+    size_t copylen, int copylen_code_delta, size_t distance_code) {
+  /* Don't rely on signed int representation, use honest casts. */
+  uint32_t delta = (uint8_t)((int8_t)copylen_code_delta);
+  self->insert_len_ = (uint32_t)insertlen;
+  self->copy_len_ = (uint32_t)(copylen | (delta << 25));
+  /* The distance prefix and extra bits are stored in this Command as if
+     npostfix and ndirect were 0, they are only recomputed later after the
+     clustering if needed. */
+  PrefixEncodeCopyDistance(
+      distance_code, dist->num_direct_distance_codes,
+      dist->distance_postfix_bits, &self->dist_prefix_, &self->dist_extra_);
+  GetLengthCode(
+      insertlen, (size_t)((int)copylen + copylen_code_delta),
+      TO_BROTLI_BOOL((self->dist_prefix_ & 0x3FF) == 0), &self->cmd_prefix_);
+}
+
+static BROTLI_INLINE void InitInsertCommand(Command* self, size_t insertlen) {
+  self->insert_len_ = (uint32_t)insertlen;
+  self->copy_len_ = 4 << 25;
+  self->dist_extra_ = 0;
+  self->dist_prefix_ = BROTLI_NUM_DISTANCE_SHORT_CODES;
+  GetLengthCode(insertlen, 4, BROTLI_FALSE, &self->cmd_prefix_);
+}
+
+static BROTLI_INLINE uint32_t CommandRestoreDistanceCode(
+    const Command* self, const BrotliDistanceParams* dist) {
+  if ((self->dist_prefix_ & 0x3FFu) <
+      BROTLI_NUM_DISTANCE_SHORT_CODES + dist->num_direct_distance_codes) {
+    return self->dist_prefix_ & 0x3FFu;
+  } else {
+    uint32_t dcode = self->dist_prefix_ & 0x3FFu;
+    uint32_t nbits = self->dist_prefix_ >> 10;
+    uint32_t extra = self->dist_extra_;
+    uint32_t postfix_mask = (1U << dist->distance_postfix_bits) - 1U;
+    uint32_t hcode = (dcode - dist->num_direct_distance_codes -
+        BROTLI_NUM_DISTANCE_SHORT_CODES) >>
+        dist->distance_postfix_bits;
+    uint32_t lcode = (dcode - dist->num_direct_distance_codes -
+        BROTLI_NUM_DISTANCE_SHORT_CODES) & postfix_mask;
+    uint32_t offset = ((2U + (hcode & 1U)) << nbits) - 4U;
+    return ((offset + extra) << dist->distance_postfix_bits) + lcode +
+        dist->num_direct_distance_codes + BROTLI_NUM_DISTANCE_SHORT_CODES;
+  }
+}
+
+static BROTLI_INLINE uint32_t CommandDistanceContext(const Command* self) {
+  uint32_t r = self->cmd_prefix_ >> 6;
+  uint32_t c = self->cmd_prefix_ & 7;
+  if ((r == 0 || r == 2 || r == 4 || r == 7) && (c <= 2)) {
+    return c;
+  }
+  return 3;
+}
+
+static BROTLI_INLINE uint32_t CommandCopyLen(const Command* self) {
+  return self->copy_len_ & 0x1FFFFFF;
+}
+
+static BROTLI_INLINE uint32_t CommandCopyLenCode(const Command* self) {
+  uint32_t modifier = self->copy_len_ >> 25;
+  int32_t delta = (int8_t)((uint8_t)(modifier | ((modifier & 0x40) << 1)));
+  return (uint32_t)((int32_t)(self->copy_len_ & 0x1FFFFFF) + delta);
+}
+
+#if defined(__cplusplus) || defined(c_plusplus)
+}  /* extern "C" */
+#endif
+
+#endif  /* BROTLI_ENC_COMMAND_H_ */