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2 changes: 1 addition & 1 deletion .gha.check-license.sh
Original file line number Diff line number Diff line change
Expand Up @@ -18,7 +18,7 @@ do

for f in $d/*.go
do
grep -q "Copyright (C) 20[1-2][0-9] The [o|O]ntology Authors" $f || files="${files} $f"
grep -q "Copyright " $f || files="${files} $f"
done
done

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2 changes: 1 addition & 1 deletion .travis.check-license.sh
Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,7 @@ for d in $dirs
do
for f in $d/*.go
do
grep -q "Copyright (C) 201[0-9] The [o|O]ntology Authors" $f || files="${files} $f"
grep -q "Copyright " $f || files="${files} $f"
done
done

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18 changes: 18 additions & 0 deletions core/bloombits/doc.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,18 @@
// Copyright 2017 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

// Package bloombits implements bloom filtering on batches of data.
package bloombits
93 changes: 93 additions & 0 deletions core/bloombits/generator.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,93 @@
// Copyright 2017 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package bloombits

import (
"errors"

"github.com/ethereum/go-ethereum/core/types"
)

var (
// errSectionOutOfBounds is returned if the user tried to add more bloom filters
// to the batch than available space, or if tries to retrieve above the capacity.
errSectionOutOfBounds = errors.New("section out of bounds")

// errBloomBitOutOfBounds is returned if the user tried to retrieve specified
// bit bloom above the capacity.
errBloomBitOutOfBounds = errors.New("bloom bit out of bounds")
)

// Generator takes a number of bloom filters and generates the rotated bloom bits
// to be used for batched filtering.
type Generator struct {
blooms [types.BloomBitLength][]byte // Rotated blooms for per-bit matching
sections uint // Number of sections to batch together
nextSec uint // Next section to set when adding a bloom
}

// NewGenerator creates a rotated bloom generator that can iteratively fill a
// batched bloom filter's bits.
func NewGenerator(sections uint) (*Generator, error) {
if sections%8 != 0 {
return nil, errors.New("section count not multiple of 8")
}
b := &Generator{sections: sections}
for i := 0; i < types.BloomBitLength; i++ {
b.blooms[i] = make([]byte, sections/8)
}
return b, nil
}

// AddBloom takes a single bloom filter and sets the corresponding bit column
// in memory accordingly.
func (b *Generator) AddBloom(index uint, bloom types.Bloom) error {
// Make sure we're not adding more bloom filters than our capacity
if b.nextSec >= b.sections {
return errSectionOutOfBounds
}
if b.nextSec != index {
return errors.New("bloom filter with unexpected index")
}
// Rotate the bloom and insert into our collection
byteIndex := b.nextSec / 8
bitMask := byte(1) << byte(7-b.nextSec%8)

for i := 0; i < types.BloomBitLength; i++ {
bloomByteIndex := types.BloomByteLength - 1 - i/8
bloomBitMask := byte(1) << byte(i%8)

if (bloom[bloomByteIndex] & bloomBitMask) != 0 {
b.blooms[i][byteIndex] |= bitMask
}
}
b.nextSec++

return nil
}

// Bitset returns the bit vector belonging to the given bit index after all
// blooms have been added.
func (b *Generator) Bitset(idx uint) ([]byte, error) {
if b.nextSec != b.sections {
return nil, errors.New("bloom not fully generated yet")
}
if idx >= types.BloomBitLength {
return nil, errBloomBitOutOfBounds
}
return b.blooms[idx], nil
}
60 changes: 60 additions & 0 deletions core/bloombits/generator_test.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,60 @@
// Copyright 2017 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package bloombits

import (
"bytes"
"math/rand"
"testing"

"github.com/ethereum/go-ethereum/core/types"
)

// Tests that batched bloom bits are correctly rotated from the input bloom
// filters.
func TestGenerator(t *testing.T) {
// Generate the input and the rotated output
var input, output [types.BloomBitLength][types.BloomByteLength]byte

for i := 0; i < types.BloomBitLength; i++ {
for j := 0; j < types.BloomBitLength; j++ {
bit := byte(rand.Int() % 2)

input[i][j/8] |= bit << byte(7-j%8)
output[types.BloomBitLength-1-j][i/8] |= bit << byte(7-i%8)
}
}
// Crunch the input through the generator and verify the result
gen, err := NewGenerator(types.BloomBitLength)
if err != nil {
t.Fatalf("failed to create bloombit generator: %v", err)
}
for i, bloom := range input {
if err := gen.AddBloom(uint(i), bloom); err != nil {
t.Fatalf("bloom %d: failed to add: %v", i, err)
}
}
for i, want := range output {
have, err := gen.Bitset(uint(i))
if err != nil {
t.Fatalf("output %d: failed to retrieve bits: %v", i, err)
}
if !bytes.Equal(have, want[:]) {
t.Errorf("output %d: bit vector mismatch have %x, want %x", i, have, want)
}
}
}
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