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Use standard merge algorithm for merging values
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The previous version was very innefficient due to the benchmarks used
to optimize it having a bug.  This version always allocates a new
slice, but is O(n).
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@jwilder
jwilder committed Mar 15, 2017
1 parent 4d37c9d commit a4cfeac
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Showing 2 changed files with 76 additions and 268 deletions.
290 changes: 65 additions & 225 deletions tsdb/engine/tsm1/encoding.gen.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -140,52 +140,20 @@ func (a Values) Merge(b Values) Values {
return append(b, a...)
}

for i := 0; i < len(a) && len(b) > 0; i++ {
av, bv := a[i].UnixNano(), b[0].UnixNano()
// Value in a is greater than B, we need to merge
if av > bv {
// Save value in a
temp := a[i]

// Overwrite a with b
a[i] = b[0]

// Slide all values of b down 1
copy(b, b[1:])
b = b[:len(b)-1]

var k int
if len(b) > 0 && av > b[len(b)-1].UnixNano() {
// Fast path where a is after b, we skip the search
k = len(b)
} else {
// See where value we save from a should be inserted in b to keep b sorted
k = sort.Search(len(b), func(i int) bool { return b[i].UnixNano() >= temp.UnixNano() })
}

if k == len(b) {
// Last position?
b = append(b, temp)
} else if b[k].UnixNano() != temp.UnixNano() {
// Save the last element, since it will get overwritten
last := b[len(b)-1]
// Somewhere in the middle of b, insert it only if it's not a duplicate
copy(b[k+1:], b[k:])
// Add the last vale to the end
b = append(b, last)
b[k] = temp
}
} else if av == bv {
// Value in a an b are the same, use b
a[i] = b[0]
b = b[1:]
}
}

if len(b) > 0 {
return append(a, b...)
out := make(Values, 0, len(a)+len(b))
for len(a) > 0 && len(b) > 0 {
if a[0].UnixNano() < b[0].UnixNano() {
out, a = append(out, a[0]), a[1:]
} else if len(b) > 0 && a[0].UnixNano() == b[0].UnixNano() {
a = a[1:]
} else {
out, b = append(out, b[0]), b[1:]
}
}
return a
if len(a) > 0 {
return append(out, a...)
}
return append(out, b...)
}

// Sort methods
Expand Down Expand Up @@ -322,52 +290,20 @@ func (a FloatValues) Merge(b FloatValues) FloatValues {
return append(b, a...)
}

for i := 0; i < len(a) && len(b) > 0; i++ {
av, bv := a[i].UnixNano(), b[0].UnixNano()
// Value in a is greater than B, we need to merge
if av > bv {
// Save value in a
temp := a[i]

// Overwrite a with b
a[i] = b[0]

// Slide all values of b down 1
copy(b, b[1:])
b = b[:len(b)-1]

var k int
if len(b) > 0 && av > b[len(b)-1].UnixNano() {
// Fast path where a is after b, we skip the search
k = len(b)
} else {
// See where value we save from a should be inserted in b to keep b sorted
k = sort.Search(len(b), func(i int) bool { return b[i].UnixNano() >= temp.UnixNano() })
}

if k == len(b) {
// Last position?
b = append(b, temp)
} else if b[k].UnixNano() != temp.UnixNano() {
// Save the last element, since it will get overwritten
last := b[len(b)-1]
// Somewhere in the middle of b, insert it only if it's not a duplicate
copy(b[k+1:], b[k:])
// Add the last vale to the end
b = append(b, last)
b[k] = temp
}
} else if av == bv {
// Value in a an b are the same, use b
a[i] = b[0]
b = b[1:]
}
}

if len(b) > 0 {
return append(a, b...)
out := make(FloatValues, 0, len(a)+len(b))
for len(a) > 0 && len(b) > 0 {
if a[0].UnixNano() < b[0].UnixNano() {
out, a = append(out, a[0]), a[1:]
} else if len(b) > 0 && a[0].UnixNano() == b[0].UnixNano() {
a = a[1:]
} else {
out, b = append(out, b[0]), b[1:]
}
}
if len(a) > 0 {
return append(out, a...)
}
return a
return append(out, b...)
}

// Sort methods
Expand Down Expand Up @@ -504,52 +440,20 @@ func (a IntegerValues) Merge(b IntegerValues) IntegerValues {
return append(b, a...)
}

for i := 0; i < len(a) && len(b) > 0; i++ {
av, bv := a[i].UnixNano(), b[0].UnixNano()
// Value in a is greater than B, we need to merge
if av > bv {
// Save value in a
temp := a[i]

// Overwrite a with b
a[i] = b[0]

// Slide all values of b down 1
copy(b, b[1:])
b = b[:len(b)-1]

var k int
if len(b) > 0 && av > b[len(b)-1].UnixNano() {
// Fast path where a is after b, we skip the search
k = len(b)
} else {
// See where value we save from a should be inserted in b to keep b sorted
k = sort.Search(len(b), func(i int) bool { return b[i].UnixNano() >= temp.UnixNano() })
}

if k == len(b) {
// Last position?
b = append(b, temp)
} else if b[k].UnixNano() != temp.UnixNano() {
// Save the last element, since it will get overwritten
last := b[len(b)-1]
// Somewhere in the middle of b, insert it only if it's not a duplicate
copy(b[k+1:], b[k:])
// Add the last vale to the end
b = append(b, last)
b[k] = temp
}
} else if av == bv {
// Value in a an b are the same, use b
a[i] = b[0]
b = b[1:]
}
}

if len(b) > 0 {
return append(a, b...)
out := make(IntegerValues, 0, len(a)+len(b))
for len(a) > 0 && len(b) > 0 {
if a[0].UnixNano() < b[0].UnixNano() {
out, a = append(out, a[0]), a[1:]
} else if len(b) > 0 && a[0].UnixNano() == b[0].UnixNano() {
a = a[1:]
} else {
out, b = append(out, b[0]), b[1:]
}
}
return a
if len(a) > 0 {
return append(out, a...)
}
return append(out, b...)
}

// Sort methods
Expand Down Expand Up @@ -686,52 +590,20 @@ func (a StringValues) Merge(b StringValues) StringValues {
return append(b, a...)
}

for i := 0; i < len(a) && len(b) > 0; i++ {
av, bv := a[i].UnixNano(), b[0].UnixNano()
// Value in a is greater than B, we need to merge
if av > bv {
// Save value in a
temp := a[i]

// Overwrite a with b
a[i] = b[0]

// Slide all values of b down 1
copy(b, b[1:])
b = b[:len(b)-1]

var k int
if len(b) > 0 && av > b[len(b)-1].UnixNano() {
// Fast path where a is after b, we skip the search
k = len(b)
} else {
// See where value we save from a should be inserted in b to keep b sorted
k = sort.Search(len(b), func(i int) bool { return b[i].UnixNano() >= temp.UnixNano() })
}

if k == len(b) {
// Last position?
b = append(b, temp)
} else if b[k].UnixNano() != temp.UnixNano() {
// Save the last element, since it will get overwritten
last := b[len(b)-1]
// Somewhere in the middle of b, insert it only if it's not a duplicate
copy(b[k+1:], b[k:])
// Add the last vale to the end
b = append(b, last)
b[k] = temp
}
} else if av == bv {
// Value in a an b are the same, use b
a[i] = b[0]
b = b[1:]
}
}

if len(b) > 0 {
return append(a, b...)
out := make(StringValues, 0, len(a)+len(b))
for len(a) > 0 && len(b) > 0 {
if a[0].UnixNano() < b[0].UnixNano() {
out, a = append(out, a[0]), a[1:]
} else if len(b) > 0 && a[0].UnixNano() == b[0].UnixNano() {
a = a[1:]
} else {
out, b = append(out, b[0]), b[1:]
}
}
if len(a) > 0 {
return append(out, a...)
}
return a
return append(out, b...)
}

// Sort methods
Expand Down Expand Up @@ -868,52 +740,20 @@ func (a BooleanValues) Merge(b BooleanValues) BooleanValues {
return append(b, a...)
}

for i := 0; i < len(a) && len(b) > 0; i++ {
av, bv := a[i].UnixNano(), b[0].UnixNano()
// Value in a is greater than B, we need to merge
if av > bv {
// Save value in a
temp := a[i]

// Overwrite a with b
a[i] = b[0]

// Slide all values of b down 1
copy(b, b[1:])
b = b[:len(b)-1]

var k int
if len(b) > 0 && av > b[len(b)-1].UnixNano() {
// Fast path where a is after b, we skip the search
k = len(b)
} else {
// See where value we save from a should be inserted in b to keep b sorted
k = sort.Search(len(b), func(i int) bool { return b[i].UnixNano() >= temp.UnixNano() })
}

if k == len(b) {
// Last position?
b = append(b, temp)
} else if b[k].UnixNano() != temp.UnixNano() {
// Save the last element, since it will get overwritten
last := b[len(b)-1]
// Somewhere in the middle of b, insert it only if it's not a duplicate
copy(b[k+1:], b[k:])
// Add the last vale to the end
b = append(b, last)
b[k] = temp
}
} else if av == bv {
// Value in a an b are the same, use b
a[i] = b[0]
b = b[1:]
}
}

if len(b) > 0 {
return append(a, b...)
out := make(BooleanValues, 0, len(a)+len(b))
for len(a) > 0 && len(b) > 0 {
if a[0].UnixNano() < b[0].UnixNano() {
out, a = append(out, a[0]), a[1:]
} else if len(b) > 0 && a[0].UnixNano() == b[0].UnixNano() {
a = a[1:]
} else {
out, b = append(out, b[0]), b[1:]
}
}
if len(a) > 0 {
return append(out, a...)
}
return a
return append(out, b...)
}

// Sort methods
Expand Down
54 changes: 11 additions & 43 deletions tsdb/engine/tsm1/encoding.gen.go.tmpl
View file
Original file line number Diff line number Diff line change
Expand Up @@ -137,52 +137,20 @@ func (a {{.Name}}Values) Merge(b {{.Name}}Values) {{.Name}}Values {
return append(b, a...)
}

for i := 0; i < len(a) && len(b) > 0; i++ {
av, bv := a[i].UnixNano(), b[0].UnixNano()
// Value in a is greater than B, we need to merge
if av > bv {
// Save value in a
temp := a[i]

// Overwrite a with b
a[i] = b[0]

// Slide all values of b down 1
copy(b, b[1:])
b = b[:len(b)-1]

var k int
if len(b) > 0 && av > b[len(b)-1].UnixNano() {
// Fast path where a is after b, we skip the search
k = len(b)
} else {
// See where value we save from a should be inserted in b to keep b sorted
k = sort.Search(len(b), func(i int) bool { return b[i].UnixNano() >= temp.UnixNano() })
}

if k == len(b) {
// Last position?
b = append(b, temp)
} else if b[k].UnixNano() != temp.UnixNano() {
// Save the last element, since it will get overwritten
last := b[len(b)-1]
// Somewhere in the middle of b, insert it only if it's not a duplicate
copy(b[k+1:], b[k:])
// Add the last vale to the end
b = append(b, last)
b[k] = temp
}
} else if av == bv {
// Value in a an b are the same, use b
a[i] = b[0]
b = b[1:]
out := make({{.Name}}Values, 0, len(a)+len(b))
for len(a) > 0 && len(b) > 0 {
if a[0].UnixNano() < b[0].UnixNano() {
out, a = append(out, a[0]), a[1:]
} else if len(b) > 0 && a[0].UnixNano() == b[0].UnixNano() {
a = a[1:]
} else {
out, b = append(out, b[0]), b[1:]
}
}

if len(b) > 0 {
return append(a, b...)
if len(a) > 0 {
return append(out, a...)
}
return a
return append(out, b...)
}

// Sort methods
Expand Down

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