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map: optimize free() and keys() (#7152)

pull/7153/head
ka-weihe 2020-12-06 00:24:24 +01:00 committed by GitHub
parent 8adb1acf31
commit 5a7fdb0610
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 77 additions and 83 deletions
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159
vlib/builtin/map.v
View File

@ -3,7 +3,7 @@
// that can be found in the LICENSE file.
module builtin
//import hash.wyhash as hash
// import hash.wyhash as hash
import hash
/*
@ -56,7 +56,6 @@ find the index for their meta's in the new array. Instead of rehashing compl-
etely, it simply uses the cached-hashbits stored in the meta, resulting in
much faster rehashing.
*/
const (
// Number of bits from the hash stored for each entry
hashbits = 24
@ -98,10 +97,10 @@ struct DenseArray {
value_bytes int
slot_bytes int // sum of 2 fields above
mut:
cap int
len int
deletes u32 // count
data byteptr // array of interspersed key data and value data
cap int
len int
deletes u32 // count
data byteptr // array of interspersed key data and value data
}
[inline]
@ -116,7 +115,7 @@ fn new_dense_array(key_bytes int, value_bytes int) DenseArray {
cap: cap
len: 0
deletes: 0
data: malloc(cap * slot_bytes)
data: malloc(cap * slot_bytes)
}
}
@ -204,7 +203,7 @@ mut:
extra_metas u32
pub mut:
// Number of key-values currently in the hashmap
len int
len int
}
fn new_map_1(value_bytes int) map {
@ -224,30 +223,28 @@ fn new_map_1(value_bytes int) map {
fn new_map_init(n int, value_bytes int, keys &string, values voidptr) map {
mut out := new_map_1(value_bytes)
for i in 0 .. n {
unsafe {
out.set(keys[i], byteptr(values) + i * value_bytes)
}
unsafe {out.set(keys[i], byteptr(values) + i * value_bytes)}
}
return out
}
[inline]
fn (m &map) key_to_index(key string) (u32,u32) {
fn (m &map) key_to_index(key string) (u32, u32) {
hash := hash.wyhash_c(key.str, u64(key.len), 0)
index := hash & m.cap
meta := ((hash >> m.shift) & hash_mask) | probe_inc
return u32(index),u32(meta)
return u32(index), u32(meta)
}
[inline]
fn (m &map) meta_less(_index u32, _metas u32) (u32,u32) {
fn (m &map) meta_less(_index u32, _metas u32) (u32, u32) {
mut index := _index
mut meta := _metas
for meta < unsafe {m.metas[index]} {
index += 2
meta += probe_inc
}
return index,meta
return index, meta
}
[inline]
@ -261,12 +258,10 @@ fn (mut m map) meta_greater(_index u32, _metas u32, kvi u32) {
tmp_meta := m.metas[index]
m.metas[index] = meta
meta = tmp_meta
}
tmp_index := unsafe {m.metas[index + 1]}
unsafe {
tmp_index := m.metas[index + 1]
m.metas[index + 1] = kv_index
kv_index = tmp_index
}
kv_index = tmp_index
}
index += 2
meta += probe_inc
@ -305,8 +300,8 @@ fn (mut m map) set(k string, value voidptr) {
if load_factor > max_load_factor {
m.expand()
}
mut index,mut meta := m.key_to_index(key)
index,meta = m.meta_less(index, meta)
mut index, mut meta := m.key_to_index(key)
index, meta = m.meta_less(index, meta)
// While we might have a match
for meta == unsafe {m.metas[index]} {
kv_index := int(unsafe {m.metas[index + 1]})
@ -335,8 +330,7 @@ fn (mut m map) expand() {
m.shift += max_cached_hashbits
m.cached_hashbits = max_cached_hashbits
m.rehash()
}
else {
} else {
m.cached_rehash(old_cap)
m.cached_hashbits--
}
@ -359,8 +353,8 @@ fn (mut m map) rehash() {
continue
}
pkey := unsafe {&string(m.key_values.key(i))}
mut index,mut meta := m.key_to_index(*pkey)
index,meta = m.meta_less(index, meta)
mut index, mut meta := m.key_to_index(*pkey)
index, meta = m.meta_less(index, meta)
m.meta_greater(index, meta, u32(i))
}
}
@ -381,13 +375,11 @@ fn (mut m map) cached_rehash(old_cap u32) {
old_index := (i - old_probe_count) & (m.cap >> 1)
mut index := (old_index | (old_meta << m.shift)) & m.cap
mut meta := (old_meta & hash_mask) | probe_inc
index,meta = m.meta_less(index, meta)
index, meta = m.meta_less(index, meta)
kv_index := unsafe {old_metas[i + 1]}
m.meta_greater(index, meta, kv_index)
}
unsafe{
free(old_metas)
}
unsafe {free(old_metas)}
}
// This method is used for assignment operators. If the argument-key
@ -395,7 +387,7 @@ fn (mut m map) cached_rehash(old_cap u32) {
// If the key exists, its respective value is returned.
fn (mut m map) get_and_set(key string, zero voidptr) voidptr {
for {
mut index,mut meta := m.key_to_index(key)
mut index, mut meta := m.key_to_index(key)
for {
if meta == unsafe {m.metas[index]} {
kv_index := int(unsafe {m.metas[index + 1]})
@ -406,7 +398,9 @@ fn (mut m map) get_and_set(key string, zero voidptr) voidptr {
}
index += 2
meta += probe_inc
if meta > unsafe {m.metas[index]} { break }
if meta > unsafe {m.metas[index]} {
break
}
}
// Key not found, insert key with zero-value
m.set(key, zero)
@ -419,7 +413,7 @@ fn (mut m map) get_and_set(key string, zero voidptr) voidptr {
// the method returns a reference to its mapped value.
// If not, a zero/default value is returned.
fn (m map) get(key string, zero voidptr) voidptr {
mut index,mut meta := m.key_to_index(key)
mut index, mut meta := m.key_to_index(key)
for {
if meta == unsafe {m.metas[index]} {
kv_index := int(unsafe {m.metas[index + 1]})
@ -430,14 +424,16 @@ fn (m map) get(key string, zero voidptr) voidptr {
}
index += 2
meta += probe_inc
if meta > unsafe {m.metas[index]} { break }
if meta > unsafe {m.metas[index]} {
break
}
}
return zero
}
// Checks whether a particular key exists in the map.
fn (m map) exists(key string) bool {
mut index,mut meta := m.key_to_index(key)
mut index, mut meta := m.key_to_index(key)
for {
if meta == unsafe {m.metas[index]} {
kv_index := int(unsafe {m.metas[index + 1]})
@ -448,15 +444,17 @@ fn (m map) exists(key string) bool {
}
index += 2
meta += probe_inc
if meta > unsafe {m.metas[index]} { break }
if meta > unsafe {m.metas[index]} {
break
}
}
return false
}
// Removes the mapping of a particular key from the map.
pub fn (mut m map) delete(key string) {
mut index,mut meta := m.key_to_index(key)
index,meta = m.meta_less(index, meta)
mut index, mut meta := m.key_to_index(key)
index, meta = m.meta_less(index, meta)
// Perform backwards shifting
for meta == unsafe {m.metas[index]} {
kv_index := int(unsafe {m.metas[index + 1]})
@ -496,10 +494,17 @@ pub fn (mut m map) delete(key string) {
}
// Returns all keys in the map.
// TODO: add optimization in case of no deletes
pub fn (m &map) keys() []string {
mut keys := []string{ len:m.len }
mut keys := []string{len: m.len}
mut j := 0
if m.key_values.deletes == 0 {
for i := 0; i < m.key_values.len; i++ {
pkey := unsafe {&string(m.key_values.key(i))}
keys[j] = pkey.clone()
j++
}
return keys
}
for i := 0; i < m.key_values.len; i++ {
if !m.key_values.has_index(i) {
continue
@ -513,14 +518,14 @@ pub fn (m &map) keys() []string {
[unsafe]
pub fn (d DenseArray) clone() DenseArray {
res := DenseArray {
key_bytes: d.key_bytes
res := DenseArray{
key_bytes: d.key_bytes
value_bytes: d.value_bytes
slot_bytes: d.slot_bytes
cap: d.cap
len: d.len
deletes: d.deletes
data: unsafe {memdup(d.data, d.cap * d.slot_bytes)}
slot_bytes: d.slot_bytes
cap: d.cap
len: d.len
deletes: d.deletes
data: unsafe {memdup(d.data, d.cap * d.slot_bytes)}
}
// FIXME clone each key
return res
@ -530,51 +535,39 @@ pub fn (d DenseArray) clone() DenseArray {
pub fn (m map) clone() map {
metasize := int(sizeof(u32) * (m.cap + 2 + m.extra_metas))
res := map{
value_bytes: m.value_bytes
cap: m.cap
value_bytes: m.value_bytes
cap: m.cap
cached_hashbits: m.cached_hashbits
shift: m.shift
key_values: unsafe {m.key_values.clone()}
metas: &u32(malloc(metasize))
extra_metas: m.extra_metas
len: m.len
}
unsafe {
C.memcpy(res.metas, m.metas, metasize)
shift: m.shift
key_values: unsafe {m.key_values.clone()}
metas: &u32(malloc(metasize))
extra_metas: m.extra_metas
len: m.len
}
unsafe {C.memcpy(res.metas, m.metas, metasize)}
return res
}
[unsafe]
pub fn (m &map) free() {
unsafe {
free(m.metas)
}
for i := 0; i < m.key_values.len; i++ {
if !m.key_values.has_index(i) {
continue
unsafe {free(m.metas)}
if m.key_values.deletes == 0 {
for i := 0; i < m.key_values.len; i++ {
unsafe {
pkey := &string(m.key_values.key(i))
(*pkey).free()
}
}
unsafe {
pkey := &string(m.key_values.key(i))
(*pkey).free()
} else {
for i := 0; i < m.key_values.len; i++ {
if !m.key_values.has_index(i) {
continue
}
unsafe {
pkey := &string(m.key_values.key(i))
(*pkey).free()
}
}
}
unsafe {
free(m.key_values.data)
}
unsafe {free(m.key_values.data)}
}
/*
pub fn (m map_string) str() string {
if m.len == 0 {
return '{}'
}
mut sb := strings.new_builder(50)
sb.writeln('{')
for key, val in m {
sb.writeln(' "$key" => "$val"')
}
sb.writeln('}')
return sb.str()
}
*/

1
vlib/v/gen/cgen.v
View File

@ -1234,6 +1234,7 @@ fn (mut g Gen) for_in(it ast.ForInStmt) {
g.expr(it.cond)
g.writeln(';')
g.writeln('for (int $idx = 0; $idx < ${atmp}.key_values.len; ++$idx) {')
// TODO: don't have this check when the map has no deleted elements
g.writeln('\tif (!DenseArray_has_index(&${atmp}.key_values, $idx)) {continue;}')
if it.key_var != '_' {
key_styp := g.typ(it.key_type)