Update brotli to v1.0.0-snapshot.

third_party/brotli/enc/literal_cost.c

 /* Copyright 2013 Google Inc. All Rights Reserved.
 
    Distributed under MIT license.
    See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
 */
 
-// Literal cost model to allow backward reference replacement to be efficient.
+/* Literal cost model to allow backward reference replacement to be efficient.
+*/
 
 #include "./literal_cost.h"
 
-#include <math.h>
-#include <algorithm>
-
+#include <brotli/types.h>
 #include "./fast_log.h"
-#include "./types.h"
+#include "./port.h"
 #include "./utf8_util.h"
 
-namespace brotli {
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
 
 static size_t UTF8Position(size_t last, size_t c, size_t clamp) {
   if (c < 128) {
-    return 0;  // Next one is the 'Byte 1' again.
-  } else if (c >= 192) {  // Next one is the 'Byte 2' of utf-8 encoding.
-    return std::min<size_t>(1, clamp);
+    return 0;  /* Next one is the 'Byte 1' again. */
+  } else if (c >= 192) {  /* Next one is the 'Byte 2' of utf-8 encoding. */
+    return BROTLI_MIN(size_t, 1, clamp);
   } else {
-    // Let's decide over the last byte if this ends the sequence.
+    /* Let's decide over the last byte if this ends the sequence. */
     if (last < 0xe0) {
-      return 0;  // Completed two or three byte coding.
-    } else {  // Next one is the 'Byte 3' of utf-8 encoding.
-      return std::min<size_t>(2, clamp);
+      return 0;  /* Completed two or three byte coding. */
+    } else {  /* Next one is the 'Byte 3' of utf-8 encoding. */
+      return BROTLI_MIN(size_t, 2, clamp);
     }
   }
 }
 
 static size_t DecideMultiByteStatsLevel(size_t pos, size_t len, size_t mask,
                                         const uint8_t *data) {
   size_t counts[3] = { 0 };
-  size_t max_utf8 = 1;  // should be 2, but 1 compresses better.
+  size_t max_utf8 = 1;  /* should be 2, but 1 compresses better. */
   size_t last_c = 0;
   size_t utf8_pos = 0;
-  for (size_t i = 0; i < len; ++i) {
+  size_t i;
+  for (i = 0; i < len; ++i) {
     size_t c = data[(pos + i) & mask];
     utf8_pos = UTF8Position(last_c, c, 2);
     ++counts[utf8_pos];
     last_c = c;
   }
   if (counts[2] < 500) {
     max_utf8 = 1;
   }
   if (counts[1] + counts[2] < 25) {
     max_utf8 = 0;
   }
   return max_utf8;
 }
 
 static void EstimateBitCostsForLiteralsUTF8(size_t pos, size_t len, size_t mask,
                                             const uint8_t *data, float *cost) {
-
-  // max_utf8 is 0 (normal ascii single byte modeling),
-  // 1 (for 2-byte utf-8 modeling), or 2 (for 3-byte utf-8 modeling).
+  /* max_utf8 is 0 (normal ASCII single byte modeling),
+     1 (for 2-byte UTF-8 modeling), or 2 (for 3-byte UTF-8 modeling). */
   const size_t max_utf8 = DecideMultiByteStatsLevel(pos, len, mask, data);
   size_t histogram[3][256] = { { 0 } };
   size_t window_half = 495;
-  size_t in_window = std::min(window_half, len);
+  size_t in_window = BROTLI_MIN(size_t, window_half, len);
   size_t in_window_utf8[3] = { 0 };
 
-  // Bootstrap histograms.
-  size_t last_c = 0;
-  size_t utf8_pos = 0;
-  for (size_t i = 0; i < in_window; ++i) {
-    size_t c = data[(pos + i) & mask];
-    ++histogram[utf8_pos][c];
-    ++in_window_utf8[utf8_pos];
-    utf8_pos = UTF8Position(last_c, c, max_utf8);
-    last_c = c;
+
+  size_t i;
+  {  /* Bootstrap histograms. */
+    size_t last_c = 0;
+    size_t utf8_pos = 0;
+    for (i = 0; i < in_window; ++i) {
+      size_t c = data[(pos + i) & mask];
+      ++histogram[utf8_pos][c];
+      ++in_window_utf8[utf8_pos];
+      utf8_pos = UTF8Position(last_c, c, max_utf8);
+      last_c = c;
+    }
   }
 
-  // Compute bit costs with sliding window.
-  for (size_t i = 0; i < len; ++i) {
+  /* Compute bit costs with sliding window. */
+  for (i = 0; i < len; ++i) {
     if (i >= window_half) {
-      // Remove a byte in the past.
-      size_t c = i < window_half + 1 ?
-          0 : data[(pos + i - window_half - 1) & mask];
-      size_t last_c = i < window_half + 2 ?
-          0 : data[(pos + i - window_half - 2) & mask];
+      /* Remove a byte in the past. */
+      size_t c =
+          i < window_half + 1 ? 0 : data[(pos + i - window_half - 1) & mask];
+      size_t last_c =
+          i < window_half + 2 ? 0 : data[(pos + i - window_half - 2) & mask];
       size_t utf8_pos2 = UTF8Position(last_c, c, max_utf8);
       --histogram[utf8_pos2][data[(pos + i - window_half) & mask]];
       --in_window_utf8[utf8_pos2];
     }
     if (i + window_half < len) {
-      // Add a byte in the future.
+      /* Add a byte in the future. */
       size_t c = data[(pos + i + window_half - 1) & mask];
       size_t last_c = data[(pos + i + window_half - 2) & mask];
       size_t utf8_pos2 = UTF8Position(last_c, c, max_utf8);
       ++histogram[utf8_pos2][data[(pos + i + window_half) & mask]];
       ++in_window_utf8[utf8_pos2];
     }
-    size_t c = i < 1 ? 0 : data[(pos + i - 1) & mask];
-    size_t last_c = i < 2 ? 0 : data[(pos + i - 2) & mask];
-    size_t utf8_pos = UTF8Position(last_c, c, max_utf8);
-    size_t masked_pos = (pos + i) & mask;
-    size_t histo = histogram[utf8_pos][data[masked_pos]];
-    if (histo == 0) {
-      histo = 1;
+    {
+      size_t c = i < 1 ? 0 : data[(pos + i - 1) & mask];
+      size_t last_c = i < 2 ? 0 : data[(pos + i - 2) & mask];
+      size_t utf8_pos = UTF8Position(last_c, c, max_utf8);
+      size_t masked_pos = (pos + i) & mask;
+      size_t histo = histogram[utf8_pos][data[masked_pos]];
+      double lit_cost;
+      if (histo == 0) {
+        histo = 1;
+      }
+      lit_cost = FastLog2(in_window_utf8[utf8_pos]) - FastLog2(histo);
+      lit_cost += 0.02905;
+      if (lit_cost < 1.0) {
+        lit_cost *= 0.5;
+        lit_cost += 0.5;
+      }
+      /* Make the first bytes more expensive -- seems to help, not sure why.
+         Perhaps because the entropy source is changing its properties
+         rapidly in the beginning of the file, perhaps because the beginning
+         of the data is a statistical "anomaly". */
+      if (i < 2000) {
+        lit_cost += 0.7 - ((double)(2000 - i) / 2000.0 * 0.35);
+      }
+      cost[i] = (float)lit_cost;
     }
-    double lit_cost = FastLog2(in_window_utf8[utf8_pos]) - FastLog2(histo);
-    lit_cost += 0.02905;
-    if (lit_cost < 1.0) {
-      lit_cost *= 0.5;
-      lit_cost += 0.5;
-    }
-    // Make the first bytes more expensive -- seems to help, not sure why.
-    // Perhaps because the entropy source is changing its properties
-    // rapidly in the beginning of the file, perhaps because the beginning
-    // of the data is a statistical "anomaly".
-    if (i < 2000) {
-      lit_cost += 0.7 - (static_cast<double>(2000 - i) / 2000.0 * 0.35);
-    }
-    cost[i] = static_cast<float>(lit_cost);
   }
 }
 
-void EstimateBitCostsForLiterals(size_t pos, size_t len, size_t mask,
-                                 const uint8_t *data, float *cost) {
-  if (IsMostlyUTF8(data, pos, mask, len, kMinUTF8Ratio)) {
+void BrotliEstimateBitCostsForLiterals(size_t pos, size_t len, size_t mask,
+                                       const uint8_t *data, float *cost) {
+  if (BrotliIsMostlyUTF8(data, pos, mask, len, kMinUTF8Ratio)) {
     EstimateBitCostsForLiteralsUTF8(pos, len, mask, data, cost);
     return;
-  }
-  size_t histogram[256] = { 0 };
-  size_t window_half = 2000;
-  size_t in_window = std::min(window_half, len);
+  } else {
+    size_t histogram[256] = { 0 };
+    size_t window_half = 2000;
+    size_t in_window = BROTLI_MIN(size_t, window_half, len);
 
-  // Bootstrap histogram.
-  for (size_t i = 0; i < in_window; ++i) {
-    ++histogram[data[(pos + i) & mask]];
-  }
+    /* Bootstrap histogram. */
+    size_t i;
+    for (i = 0; i < in_window; ++i) {
+      ++histogram[data[(pos + i) & mask]];
+    }
 
-  // Compute bit costs with sliding window.
-  for (size_t i = 0; i < len; ++i) {
-    if (i >= window_half) {
-      // Remove a byte in the past.
-      --histogram[data[(pos + i - window_half) & mask]];
-      --in_window;
+    /* Compute bit costs with sliding window. */
+    for (i = 0; i < len; ++i) {
+      size_t histo;
+      if (i >= window_half) {
+        /* Remove a byte in the past. */
+        --histogram[data[(pos + i - window_half) & mask]];
+        --in_window;
+      }
+      if (i + window_half < len) {
+        /* Add a byte in the future. */
+        ++histogram[data[(pos + i + window_half) & mask]];
+        ++in_window;
+      }
+      histo = histogram[data[(pos + i) & mask]];
+      if (histo == 0) {
+        histo = 1;
+      }
+      {
+        double lit_cost = FastLog2(in_window) - FastLog2(histo);
+        lit_cost += 0.029;
+        if (lit_cost < 1.0) {
+          lit_cost *= 0.5;
+          lit_cost += 0.5;
+        }
+        cost[i] = (float)lit_cost;
+      }
     }
-    if (i + window_half < len) {
-      // Add a byte in the future.
-      ++histogram[data[(pos + i + window_half) & mask]];
-      ++in_window;
-    }
-    size_t histo = histogram[data[(pos + i) & mask]];
-    if (histo == 0) {
-      histo = 1;
-    }
-    double lit_cost = FastLog2(in_window) - FastLog2(histo);
-    lit_cost += 0.029;
-    if (lit_cost < 1.0) {
-      lit_cost *= 0.5;
-      lit_cost += 0.5;
-    }
-    cost[i] = static_cast<float>(lit_cost);
   }
 }
 
-
-}  // namespace brotli
+#if defined(__cplusplus) || defined(c_plusplus)
+}  /* extern "C" */
+#endif