remove hat trie

spec/array_hash_spec.cr

@@ -23,5 +23,14 @@ describe Aha do
   end
 
   it "array hash io" do
+    hash = Aha::ArrayHash(2).new
+    v1 = Bytes.new [3_u8, 4_u8].to_unsafe, 2
+    v2 = Bytes.new [5_u8, 6_u8].to_unsafe, 2
+    v3 = Bytes.new [7_u8, 8_u8].to_unsafe, 2
+    hash["abc"] = v1
+    hash["cde"] = v2
+    hash["abcd"] = v3
+    hash.save "aha.bin"
+    hash = Aha::ArrayHash(2).load "aha.bin"
   end
 end

src/aha/ac.cr

@@ -174,7 +174,7 @@ module Aha
 
     def self.load(path)
       File.open(path, "rb") do |f|
-        return AC.from_io f, Aha::ByteFormat
+        return self.from_io f, Aha::ByteFormat
       end
     end
   end

src/aha/array_hash.cr

@@ -1,6 +1,6 @@
 module Aha
   # an open address hash table
-  struct ArrayHash(N) # N is the byte num of value
+  class ArrayHash(N) # N is the byte num of value
     struct KV
       @key : Bytes
       @value : Bytes
@@ -74,7 +74,7 @@ module Aha
       if padding != 4
         (0...padding).each { |_| UInt8.from_io io, format }
       end
-      return self.new(n, m, max_m, slot_sizes, slots)
+      return self.new(n, m, max_m, slot_sizes, slots.to_unsafe)
     end
 
     def initialize(@n, @m, @max_m, @slot_sizes, @slots)
@@ -241,7 +241,7 @@ module Aha
       return ret
     end
 
-    private def try_get(key : Bytes | Array(UInt8))
+    private def try_get(key : Bytes | Array(UInt8)) : UInt8*
       get_key(key, false)
     end
 
@@ -313,7 +313,7 @@ module Aha
 
     def self.load(path)
       File.open(path, "rb") do |f|
-        return ArrayHash.from_io f, Aha::ByteFormat
+        return self.from_io f, Aha::ByteFormat
       end
     end
   end

src/aha/cedar.cr

@@ -912,7 +912,7 @@ module Aha
 
     def self.load(path)
       File.open(path, "rb") do |f|
-        return Cedar.from_io f, Aha::ByteFormat
+        return self.from_io f, Aha::ByteFormat
       end
     end
   end

src/aha/elias_fano.cr

@@ -0,0 +1,42 @@
+module Aha
+  # 用于存储单调递增的整数序列, 能够对序列进行压缩
+  struct EliasFano(T)
+    @bytes : UInt8*
+    @length : UInt64
+    @u : T
+
+    def self.round_up(val : UInt64, den : UInt64) : UInt64
+      val = val == 0 ? den : val
+      return (val % den == 0) ? val : val + (den - (val % den))
+    end
+
+    # Returns the number of lower bits required to encode each element in an
+    # array of size length with maximum value u
+    def self.get_l(u : UInt32, length : UInt32)
+      x = round_up(u.to_u64, length.to_u64) / length
+      return (sizeof(T) << 3) - Aha.leading_zero(x - 1)
+    end
+
+    def initialize(ptr : T*, @length : UInt64)
+      @u = ptr[length - 1]
+      l = self.class.get_l u, length
+      @bytes = Pointer(UInt8).malloc(compressed_size(@u, @length))
+      low_bits_offset = 0
+      high_bits_offset = round_up l * @length, 8
+      prev = 0
+      (0...@length).each do |i|
+        # @TODO
+      end
+    end
+
+    def [](idx : UInt64) : T
+    end
+
+    def self.compressed_size(u, length)
+      l = get_l u, length
+      num_low_bits = round_up l * length, 8
+      num_high_bits = round_up 2 * length, 8
+      (num_low_bits + num_high_bits) / 8
+    end
+  end
+end