From b0e33da02d062200dd41e4503ecc21fb4bd636e6 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Tue, 31 Oct 2017 20:05:37 -0600
Subject: [PATCH] Add BinSearchArrayOf<>

---
 src/hb-open-file-private.hh | 25 +++++++++++--------------
 src/hb-open-type-private.hh | 33 ++++++++++++++++++++++++++++++++-
 src/hb-ot-font.cc           |  2 +-
 3 files changed, 44 insertions(+), 16 deletions(-)

diff --git a/src/hb-open-file-private.hh b/src/hb-open-file-private.hh
index dcfdfd6ca..77caddd27 100644
--- a/src/hb-open-file-private.hh
+++ b/src/hb-open-file-private.hh
@@ -73,10 +73,9 @@ typedef struct OffsetTable
   friend struct OpenTypeFontFile;
 
   inline unsigned int get_table_count (void) const
-  { return numTables; }
+  { return tables.len; }
   inline const TableRecord& get_table (unsigned int i) const
   {
-    if (unlikely (i >= numTables)) return Null(TableRecord);
     return tables[i];
   }
   inline unsigned int get_table_tags (unsigned int start_offset,
@@ -85,26 +84,27 @@ typedef struct OffsetTable
   {
     if (table_count)
     {
-      if (start_offset >= numTables)
+      if (start_offset >= tables.len)
         *table_count = 0;
       else
-        *table_count = MIN (*table_count, numTables - start_offset);
+        *table_count = MIN (*table_count, tables.len - start_offset);
 
-      const TableRecord *sub_tables = tables + start_offset;
+      const TableRecord *sub_tables = tables.array + start_offset;
       unsigned int count = *table_count;
       for (unsigned int i = 0; i < count; i++)
 	table_tags[i] = sub_tables[i].tag;
     }
-    return numTables;
+    return tables.len;
   }
   inline bool find_table_index (hb_tag_t tag, unsigned int *table_index) const
   {
     Tag t;
     t.set (tag);
-    unsigned int count = numTables;
+    unsigned int count = tables.len;
+    /* TODO bsearch() */
     for (unsigned int i = 0; i < count; i++)
     {
-      if (t == tables[i].tag)
+      if (t == tables.array[i].tag)
       {
         if (table_index) *table_index = i;
         return true;
@@ -124,16 +124,13 @@ typedef struct OffsetTable
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
-    return_trace (c->check_struct (this) && c->check_array (tables, TableRecord::static_size, numTables));
+    return_trace (c->check_struct (this) && tables.sanitize (c));
   }
 
   protected:
   Tag		sfnt_version;	/* '\0\001\0\00' if TrueType / 'OTTO' if CFF */
-  USHORT	numTables;	/* Number of tables. */
-  USHORT	searchRangeZ;	/* (Maximum power of 2 <= numTables) x 16 */
-  USHORT	entrySelectorZ;	/* Log2(maximum power of 2 <= numTables). */
-  USHORT	rangeShiftZ;	/* NumTables x 16-searchRange. */
-  TableRecord	tables[VAR];	/* TableRecord entries. numTables items */
+  BinSearchArrayOf<TableRecord>
+		tables;
   public:
   DEFINE_SIZE_ARRAY (12, tables);
 } OpenTypeFontFace;
diff --git a/src/hb-open-type-private.hh b/src/hb-open-type-private.hh
index e41e7451f..90db791ee 100644
--- a/src/hb-open-type-private.hh
+++ b/src/hb-open-type-private.hh
@@ -1045,7 +1045,9 @@ struct HeadlessArrayOf
 };
 
 
-/* An array with sorted elements.  Supports binary searching. */
+/*
+ * An array with sorted elements.  Supports binary searching.
+ */
 template <typename Type, typename LenType=USHORT>
 struct SortedArrayOf : ArrayOf<Type, LenType>
 {
@@ -1070,6 +1072,35 @@ struct SortedArrayOf : ArrayOf<Type, LenType>
   }
 };
 
+/*
+ * Binary-search arrays
+ */
+
+struct BinSearchHeader
+{
+  inline operator uint32_t (void) const { return len; }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this));
+  }
+
+  protected:
+  USHORT	len;
+  USHORT	searchRangeZ;
+  USHORT	entrySelectorZ;
+  USHORT	rangeShiftZ;
+
+  public:
+  DEFINE_SIZE_STATIC (8);
+};
+
+template <typename Type>
+struct BinSearchArrayOf : SortedArrayOf<Type, BinSearchHeader>
+{
+};
+
 
 /* Lazy struct and blob loaders. */
 
diff --git a/src/hb-ot-font.cc b/src/hb-ot-font.cc
index 5759a30d3..38f614935 100644
--- a/src/hb-ot-font.cc
+++ b/src/hb-ot-font.cc
@@ -37,8 +37,8 @@
 #include "hb-ot-hhea-table.hh"
 #include "hb-ot-hmtx-table.hh"
 #include "hb-ot-os2-table.hh"
-#include "hb-ot-var-hvar-table.hh"
 #include "hb-ot-post-table.hh"
+#include "hb-ot-var-hvar-table.hh"
 
 
 struct hb_ot_face_metrics_accelerator_t