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#
#
# Nim's Runtime Library
# (c) Copyright 2015 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
#
type
PtrTable = ptr object
counter, max: int
data: array[0xff_ffff, (pointer, pointer)]
template hashPtr(key: pointer): int = cast[int](key) shr 8
template allocPtrTable: untyped =
cast[PtrTable](alloc0(sizeof(int)*2 + sizeof(pointer)*2*cap))
proc rehash(t: PtrTable): PtrTable =
let cap = (t.max+1) * 2
result = allocPtrTable()
result.counter = t.counter
result.max = cap-1
for i in 0..t.max:
let k = t.data[i][0]
if k != nil:
var h = hashPtr(k)
while result.data[h and result.max][0] != nil: inc h
result.data[h and result.max] = t.data[i]
dealloc t
proc initPtrTable(): PtrTable =
const cap = 32
result = allocPtrTable()
result.counter = 0
result.max = cap-1
template deinit(t: PtrTable) = dealloc(t)
proc get(t: PtrTable; key: pointer): pointer =
var h = hashPtr(key)
while true:
let k = t.data[h and t.max][0]
if k == nil: break
if k == key:
return t.data[h and t.max][1]
inc h
proc put(t: var PtrTable; key, val: pointer) =
if (t.max+1) * 2 < t.counter * 3: t = rehash(t)
var h = hashPtr(key)
while t.data[h and t.max][0] != nil: inc h
t.data[h and t.max] = (key, val)
inc t.counter
proc genericDeepCopyAux(dest, src: pointer, mt: PNimType;
tab: var PtrTable) {.benign.}
proc genericDeepCopyAux(dest, src: pointer, n: ptr TNimNode;
tab: var PtrTable) {.benign.} =
var
d = cast[ByteAddress](dest)
s = cast[ByteAddress](src)
case n.kind
of nkSlot:
genericDeepCopyAux(cast[pointer](d +% n.offset),
cast[pointer](s +% n.offset), n.typ, tab)
of nkList:
for i in 0..n.len-1:
genericDeepCopyAux(dest, src, n.sons[i], tab)
of nkCase:
var dd = selectBranch(dest, n)
var m = selectBranch(src, n)
# reset if different branches are in use; note different branches also
# imply that's not self-assignment (``x = x``)!
if m != dd and dd != nil:
genericResetAux(dest, dd)
copyMem(cast[pointer](d +% n.offset), cast[pointer](s +% n.offset),
n.typ.size)
if m != nil:
genericDeepCopyAux(dest, src, m, tab)
of nkNone: sysAssert(false, "genericDeepCopyAux")
proc genericDeepCopyAux(dest, src: pointer, mt: PNimType; tab: var PtrTable) =
var
d = cast[ByteAddress](dest)
s = cast[ByteAddress](src)
sysAssert(mt != nil, "genericDeepCopyAux 2")
case mt.kind
of tyString:
var x = cast[PPointer](dest)
var s2 = cast[PPointer](s)[]
if s2 == nil:
unsureAsgnRef(x, s2)
else:
unsureAsgnRef(x, copyDeepString(cast[NimString](s2)))
of tySequence:
var s2 = cast[PPointer](src)[]
var seq = cast[PGenericSeq](s2)
var x = cast[PPointer](dest)
if s2 == nil:
unsureAsgnRef(x, s2)
return
sysAssert(dest != nil, "genericDeepCopyAux 3")
unsureAsgnRef(x, newSeq(mt, seq.len))
var dst = cast[ByteAddress](cast[PPointer](dest)[])
for i in 0..seq.len-1:
genericDeepCopyAux(
cast[pointer](dst +% i *% mt.base.size +% GenericSeqSize),
cast[pointer](cast[ByteAddress](s2) +% i *% mt.base.size +%
GenericSeqSize),
mt.base, tab)
of tyObject:
# we need to copy m_type field for tyObject, as it could be empty for
# sequence reallocations:
if mt.base != nil:
genericDeepCopyAux(dest, src, mt.base, tab)
else:
var pint = cast[ptr PNimType](dest)
pint[] = cast[ptr PNimType](src)[]
genericDeepCopyAux(dest, src, mt.node, tab)
of tyTuple:
genericDeepCopyAux(dest, src, mt.node, tab)
of tyArray, tyArrayConstr:
for i in 0..(mt.size div mt.base.size)-1:
genericDeepCopyAux(cast[pointer](d +% i *% mt.base.size),
cast[pointer](s +% i *% mt.base.size), mt.base, tab)
of tyRef:
let s2 = cast[PPointer](src)[]
if s2 == nil:
unsureAsgnRef(cast[PPointer](dest), s2)
elif mt.base.deepcopy != nil:
let z = mt.base.deepcopy(s2)
unsureAsgnRef(cast[PPointer](dest), z)
else:
let z = tab.get(s2)
if z == nil:
when declared(usrToCell):
let x = usrToCell(s2)
let realType = x.typ
let z = newObj(realType, realType.base.size)
unsureAsgnRef(cast[PPointer](dest), z)
tab.put(s2, z)
genericDeepCopyAux(z, s2, realType.base, tab)
else:
when false:
# addition check disabled
let x = usrToCell(s2)
let realType = x.typ
sysAssert realType == mt, " types do differ"
# this version should work for any possible GC:
let typ = if mt.base.kind == tyObject: cast[ptr PNimType](s2)[] else: mt.base
let z = newObj(mt, typ.size)
unsureAsgnRef(cast[PPointer](dest), z)
tab.put(s2, z)
genericDeepCopyAux(z, s2, typ, tab)
else:
unsureAsgnRef(cast[PPointer](dest), z)
of tyPtr:
# no cycle check here, but also not really required
let s2 = cast[PPointer](src)[]
if s2 != nil and mt.base.deepcopy != nil:
cast[PPointer](dest)[] = mt.base.deepcopy(s2)
else:
cast[PPointer](dest)[] = s2
else:
copyMem(dest, src, mt.size)
proc genericDeepCopy(dest, src: pointer, mt: PNimType) {.compilerProc.} =
GC_disable()
var tab = initPtrTable()
genericDeepCopyAux(dest, src, mt, tab)
deinit tab
GC_enable()
proc genericSeqDeepCopy(dest, src: pointer, mt: PNimType) {.compilerProc.} =
# also invoked for 'string'
var src = src
genericDeepCopy(dest, addr(src), mt)
proc genericDeepCopyOpenArray(dest, src: pointer, len: int,
mt: PNimType) {.compilerproc.} =
var
d = cast[ByteAddress](dest)
s = cast[ByteAddress](src)
for i in 0..len-1:
genericDeepCopy(cast[pointer](d +% i *% mt.base.size),
cast[pointer](s +% i *% mt.base.size), mt.base)
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