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/**
* Implementation of associative arrays.
*
* Copyright: Copyright Digital Mars 2000 - 2010.
* License: <a href="http://www.boost.org/LICENSE_1_0.txt">Boost License 1.0</a>.
* Authors: Walter Bright, Sean Kelly
*/
/* Copyright Digital Mars 2000 - 2010.
* Distributed under the Boost Software License, Version 1.0.
* (See accompanying file LICENSE or copy at
* http://www.boost.org/LICENSE_1_0.txt)
*/
module rt.aaA;
private
{
import core.stdc.stdarg;
import core.stdc.string;
import core.stdc.stdio;
import core.memory;
// Convenience function to make sure the NO_INTERIOR gets set on the
// bucket array.
Entry*[] newBuckets(in size_t len) @trusted pure nothrow
{
auto ptr = cast(Entry**) GC.calloc(
len * (Entry*).sizeof, GC.BlkAttr.NO_INTERIOR);
return ptr[0..len];
}
}
// Auto-rehash and pre-allocate - Dave Fladebo
static immutable size_t[] prime_list = [
31UL,
97UL, 389UL,
1_543UL, 6_151UL,
24_593UL, 98_317UL,
393_241UL, 1_572_869UL,
6_291_469UL, 25_165_843UL,
100_663_319UL, 402_653_189UL,
1_610_612_741UL, 4_294_967_291UL,
// 8_589_934_513UL, 17_179_869_143UL
];
/* This is the type of the return value for dynamic arrays.
* It should be a type that is returned in registers.
* Although DMD will return types of Array in registers,
* gcc will not, so we instead use a 'long'.
*/
alias void[] ArrayRet_t;
struct Array
{
size_t length;
void* ptr;
}
struct Entry
{
Entry *next;
size_t hash;
/* key */
/* value */
}
struct Impl
{
Entry*[] buckets;
size_t nodes; // total number of entries
TypeInfo _keyti;
Entry*[4] binit; // initial value of buckets[]
@property const(TypeInfo) keyti() const @safe pure nothrow @nogc
{ return _keyti; }
}
/* This is the type actually seen by the programmer, although
* it is completely opaque.
*/
struct AA
{
Impl* impl;
}
/**********************************
* Align to next pointer boundary, so that
* GC won't be faced with misaligned pointers
* in value.
*/
size_t aligntsize(in size_t tsize) @safe pure nothrow @nogc
{
version (D_LP64) {
// align to 16 bytes on 64-bit
return (tsize + 15) & ~(15);
}
else {
return (tsize + size_t.sizeof - 1) & ~(size_t.sizeof - 1);
}
}
extern (C):
/****************************************************
* Determine number of entries in associative array.
*/
size_t _aaLen(in AA aa) pure nothrow @nogc
in
{
//printf("_aaLen()+\n");
//_aaInv(aa);
}
out (result)
{
size_t len = 0;
if (aa.impl)
{
foreach (const(Entry)* e; aa.impl.buckets)
{
while (e)
{ len++;
e = e.next;
}
}
}
assert(len == result);
//printf("_aaLen()-\n");
}
body
{
return aa.impl ? aa.impl.nodes : 0;
}
/*************************************************
* Get pointer to value in associative array indexed by key.
* Add entry for key if it is not already there.
*/
void* _aaGetX(AA* aa, const TypeInfo keyti, in size_t valuesize, in void* pkey)
in
{
assert(aa);
}
out (result)
{
assert(result);
assert(aa.impl !is null);
assert(aa.impl.buckets.length);
//assert(_aaInAh(*aa.a, key));
}
body
{
size_t i;
Entry *e;
//printf("keyti = %p\n", keyti);
//printf("aa = %p\n", aa);
immutable keytitsize = keyti.tsize;
if (aa.impl is null)
{ aa.impl = new Impl();
aa.impl.buckets = aa.impl.binit[];
}
//printf("aa = %p\n", aa);
//printf("aa.a = %p\n", aa.a);
aa.impl._keyti = cast() keyti;
auto key_hash = keyti.getHash(pkey);
//printf("hash = %d\n", key_hash);
i = key_hash % aa.impl.buckets.length;
auto pe = &aa.impl.buckets[i];
while ((e = *pe) !is null)
{
if (key_hash == e.hash)
{
if (keyti.equals(pkey, e + 1))
goto Lret;
}
pe = &e.next;
}
{
// Not found, create new elem
//printf("create new one\n");
size_t size = Entry.sizeof + aligntsize(keytitsize) + valuesize;
e = cast(Entry *) GC.malloc(size);
e.next = null;
e.hash = key_hash;
ubyte* ptail = cast(ubyte*)(e + 1);
memcpy(ptail, pkey, keytitsize);
memset(ptail + aligntsize(keytitsize), 0, valuesize); // zero value
*pe = e;
auto nodes = ++aa.impl.nodes;
//printf("length = %d, nodes = %d\n", aa.a.buckets.length, nodes);
if (nodes > aa.impl.buckets.length * 4)
{
//printf("rehash\n");
_aaRehash(aa,keyti);
}
}
Lret:
return cast(void *)(e + 1) + aligntsize(keytitsize);
}
/*************************************************
* Get pointer to value in associative array indexed by key.
* Returns null if it is not already there.
*/
inout(void)* _aaGetRvalueX(inout AA aa, in TypeInfo keyti, in size_t valuesize, in void* pkey)
{
//printf("_aaGetRvalue(valuesize = %u)\n", valuesize);
if (aa.impl is null)
return null;
auto keysize = aligntsize(keyti.tsize);
auto len = aa.impl.buckets.length;
if (len)
{
auto key_hash = keyti.getHash(pkey);
//printf("hash = %d\n", key_hash);
size_t i = key_hash % len;
inout(Entry)* e = aa.impl.buckets[i];
while (e !is null)
{
if (key_hash == e.hash)
{
if (keyti.equals(pkey, e + 1))
return cast(inout void *)(e + 1) + keysize;
}
e = e.next;
}
}
return null; // not found, caller will throw exception
}
/*************************************************
* Determine if key is in aa.
* Returns:
* null not in aa
* !=null in aa, return pointer to value
*/
inout(void)* _aaInX(inout AA aa, in TypeInfo keyti, in void* pkey)
in
{
}
out (result)
{
//assert(result == 0 || result == 1);
}
body
{
if (aa.impl)
{
//printf("_aaIn(), .length = %d, .ptr = %x\n", aa.a.length, cast(uint)aa.a.ptr);
auto len = aa.impl.buckets.length;
if (len)
{
auto key_hash = keyti.getHash(pkey);
//printf("hash = %d\n", key_hash);
const i = key_hash % len;
inout(Entry)* e = aa.impl.buckets[i];
while (e !is null)
{
if (key_hash == e.hash)
{
if (keyti.equals(pkey, e + 1))
return cast(inout void *)(e + 1) + aligntsize(keyti.tsize);
}
e = e.next;
}
}
}
// Not found
return null;
}
/*************************************************
* Delete key entry in aa[].
* If key is not in aa[], do nothing.
*/
bool _aaDelX(AA aa, in TypeInfo keyti, in void* pkey)
{
Entry *e;
if (aa.impl && aa.impl.buckets.length)
{
auto key_hash = keyti.getHash(pkey);
//printf("hash = %d\n", key_hash);
size_t i = key_hash % aa.impl.buckets.length;
auto pe = &aa.impl.buckets[i];
while ((e = *pe) !is null) // null means not found
{
if (key_hash == e.hash)
{
if (keyti.equals(pkey, e + 1))
{
*pe = e.next;
aa.impl.nodes--;
GC.free(e);
return true;
}
}
pe = &e.next;
}
}
return false;
}
/********************************************
* Produce array of values from aa.
*/
inout(ArrayRet_t) _aaValues(inout AA aa, in size_t keysize, in size_t valuesize) pure nothrow
{
size_t resi;
Array a;
auto alignsize = aligntsize(keysize);
if (aa.impl !is null)
{
a.length = _aaLen(aa);
a.ptr = cast(byte*) GC.malloc(a.length * valuesize,
valuesize < (void*).sizeof ? GC.BlkAttr.NO_SCAN : 0);
resi = 0;
foreach (inout(Entry)* e; aa.impl.buckets)
{
while (e)
{
memcpy(a.ptr + resi * valuesize,
cast(byte*)e + Entry.sizeof + alignsize,
valuesize);
resi++;
e = e.next;
}
}
assert(resi == a.length);
}
return *cast(inout ArrayRet_t*)(&a);
}
/********************************************
* Rehash an array.
*/
void* _aaRehash(AA* paa, in TypeInfo keyti) pure nothrow
in
{
//_aaInvAh(paa);
}
out (result)
{
//_aaInvAh(result);
}
body
{
//printf("Rehash\n");
if (paa.impl !is null)
{
auto len = _aaLen(*paa);
if (len)
{
Impl newImpl;
Impl* oldImpl = paa.impl;
size_t i;
for (i = 0; i < prime_list.length - 1; i++)
{
if (len <= prime_list[i])
break;
}
len = prime_list[i];
newImpl.buckets = newBuckets(len);
foreach (e; oldImpl.buckets)
{
while (e)
{ auto enext = e.next;
const j = e.hash % len;
e.next = newImpl.buckets[j];
newImpl.buckets[j] = e;
e = enext;
}
}
if (oldImpl.buckets.ptr == oldImpl.binit.ptr)
oldImpl.binit[] = null;
else
GC.free(oldImpl.buckets.ptr);
newImpl.nodes = oldImpl.nodes;
newImpl._keyti = oldImpl._keyti;
*paa.impl = newImpl;
}
else
{
if (paa.impl.buckets.ptr != paa.impl.binit.ptr)
GC.free(paa.impl.buckets.ptr);
paa.impl.buckets = paa.impl.binit[];
}
}
return (*paa).impl;
}
/********************************************
* Produce array of N byte keys from aa.
*/
inout(ArrayRet_t) _aaKeys(inout AA aa, in size_t keysize) pure nothrow
{
auto len = _aaLen(aa);
if (!len)
return null;
immutable blkAttr = !(aa.impl.keyti.flags & 1) ? GC.BlkAttr.NO_SCAN : 0;
auto res = (cast(byte*) GC.malloc(len * keysize, blkAttr))[0 .. len * keysize];
size_t resi = 0;
foreach (inout(Entry)* e; aa.impl.buckets)
{
while (e)
{
memcpy(&res[resi * keysize], cast(byte*)(e + 1), keysize);
resi++;
e = e.next;
}
}
assert(resi == len);
Array a;
a.length = len;
a.ptr = res.ptr;
return *cast(inout ArrayRet_t*)(&a);
}
pure nothrow unittest
{
int[string] aa;
aa["hello"] = 3;
assert(aa["hello"] == 3);
aa["hello"]++;
assert(aa["hello"] == 4);
assert(aa.length == 1);
string[] keys = aa.keys;
assert(keys.length == 1);
assert(memcmp(keys[0].ptr, cast(char*)"hello", 5) == 0);
int[] values = aa.values;
assert(values.length == 1);
assert(values[0] == 4);
aa.rehash;
assert(aa.length == 1);
assert(aa["hello"] == 4);
aa["foo"] = 1;
aa["bar"] = 2;
aa["batz"] = 3;
assert(aa.keys.length == 4);
assert(aa.values.length == 4);
foreach(a; aa.keys)
{
assert(a.length != 0);
assert(a.ptr != null);
//printf("key: %.*s -> value: %d\n", a.length, a.ptr, aa[a]);
}
foreach(v; aa.values)
{
assert(v != 0);
//printf("value: %d\n", v);
}
}
unittest // Test for Issue 10381
{
alias II = int[int];
II aa1 = [0: 1];
II aa2 = [0: 1];
II aa3 = [0: 2];
assert(aa1 == aa2); // Passes
assert( typeid(II).equals(&aa1, &aa2));
assert(!typeid(II).equals(&aa1, &aa3));
}
/**********************************************
* 'apply' for associative arrays - to support foreach
*/
// dg is D, but _aaApply() is C
extern (D) alias int delegate(void *) dg_t;
int _aaApply(AA aa, in size_t keysize, dg_t dg)
{
if (aa.impl is null)
{
return 0;
}
immutable alignsize = aligntsize(keysize);
//printf("_aaApply(aa = x%llx, keysize = %d, dg = x%llx)\n", aa.impl, keysize, dg);
foreach (e; aa.impl.buckets)
{
while (e)
{
auto result = dg(cast(void *)(e + 1) + alignsize);
if (result)
return result;
e = e.next;
}
}
return 0;
}
// dg is D, but _aaApply2() is C
extern (D) alias int delegate(void *, void *) dg2_t;
int _aaApply2(AA aa, in size_t keysize, dg2_t dg)
{
if (aa.impl is null)
{
return 0;
}
//printf("_aaApply(aa = x%llx, keysize = %d, dg = x%llx)\n", aa.impl, keysize, dg);
immutable alignsize = aligntsize(keysize);
foreach (e; aa.impl.buckets)
{
while (e)
{
auto result = dg(e + 1, cast(void *)(e + 1) + alignsize);
if (result)
return result;
e = e.next;
}
}
return 0;
}
/***********************************
* Construct an associative array of type ti from
* length pairs of key/value pairs.
*/
Impl* _d_assocarrayliteralTX(const TypeInfo_AssociativeArray ti, void[] keys, void[] values)
{
const valuesize = ti.next.tsize; // value size
const keyti = ti.key;
const keysize = keyti.tsize; // key size
const length = keys.length;
Impl* result;
//printf("_d_assocarrayliteralT(keysize = %d, valuesize = %d, length = %d)\n", keysize, valuesize, length);
//printf("tivalue = %.*s\n", typeid(ti.next).name);
assert(length == values.length);
if (length == 0 || valuesize == 0 || keysize == 0)
{
}
else
{
result = new Impl();
result._keyti = cast() keyti;
size_t i;
for (i = 0; i < prime_list.length - 1; i++)
{
if (length <= prime_list[i])
break;
}
auto len = prime_list[i];
result.buckets = newBuckets(len);
size_t keytsize = aligntsize(keysize);
for (size_t j = 0; j < length; j++)
{ auto pkey = keys.ptr + j * keysize;
auto pvalue = values.ptr + j * valuesize;
Entry* e;
auto key_hash = keyti.getHash(pkey);
//printf("hash = %d\n", key_hash);
i = key_hash % len;
auto pe = &result.buckets[i];
while (1)
{
e = *pe;
if (!e)
{
// Not found, create new elem
//printf("create new one\n");
e = cast(Entry *) cast(void*) new void[Entry.sizeof + keytsize + valuesize];
memcpy(e + 1, pkey, keysize);
e.hash = key_hash;
*pe = e;
result.nodes++;
break;
}
if (key_hash == e.hash)
{
if (keyti.equals(pkey, e + 1))
break;
}
pe = &e.next;
}
memcpy(cast(void *)(e + 1) + keytsize, pvalue, valuesize);
}
}
return result;
}
const(TypeInfo_AssociativeArray) _aaUnwrapTypeInfo(const(TypeInfo) tiRaw) pure nothrow @nogc
{
const(TypeInfo)* p = &tiRaw;
TypeInfo_AssociativeArray ti;
while (true)
{
if ((ti = cast(TypeInfo_AssociativeArray)*p) !is null)
break;
if (auto tiConst = cast(TypeInfo_Const)*p) {
// The member in object_.d and object.di differ. This is to ensure
// the file can be compiled both independently in unittest and
// collectively in generating the library. Fixing object.di
// requires changes to std.format in Phobos, fixing object_.d
// makes Phobos's unittest fail, so this hack is employed here to
// avoid irrelevant changes.
static if (is(typeof(&tiConst.base) == TypeInfo*))
p = &tiConst.base;
else
p = &tiConst.next;
} else
assert(0); // ???
}
return ti;
}
/***********************************
* Compare AA contents for equality.
* Returns:
* 1 equal
* 0 not equal
*/
int _aaEqual(in TypeInfo tiRaw, in AA e1, in AA e2)
{
//printf("_aaEqual()\n");
//printf("keyti = %.*s\n", typeid(ti.key).name);
//printf("valueti = %.*s\n", typeid(ti.next).name);
if (e1.impl is e2.impl)
return 1;
size_t len = _aaLen(e1);
if (len != _aaLen(e2))
return 0;
// Bug 9852: at this point, e1 and e2 have the same length, so if one is
// null, the other must either also be null or have zero entries, so they
// must be equal. We check this here to avoid dereferencing null later on.
if (e1.impl is null || e2.impl is null)
return 1;
// Check for Bug 5925. ti_raw could be a TypeInfo_Const, we need to unwrap
// it until reaching a real TypeInfo_AssociativeArray.
const TypeInfo_AssociativeArray ti = _aaUnwrapTypeInfo(tiRaw);
/* Algorithm: Visit each key/value pair in e1. If that key doesn't exist
* in e2, or if the value in e1 doesn't match the one in e2, the arrays
* are not equal, and exit early.
* After all pairs are checked, the arrays must be equal.
*/
const keyti = ti.key;
const valueti = ti.next;
const keysize = aligntsize(keyti.tsize);
assert(e2.impl !is null);
const len2 = e2.impl.buckets.length;
int _aaKeys_x(const(Entry)* e)
{
do
{
auto pkey = cast(void*)(e + 1);
auto pvalue = pkey + keysize;
//printf("key = %d, value = %g\n", *cast(int*)pkey, *cast(double*)pvalue);
// We have key/value for e1. See if they exist in e2
auto key_hash = keyti.getHash(pkey);
//printf("hash = %d\n", key_hash);
const i = key_hash % len2;
const(Entry)* f = e2.impl.buckets[i];
while (1)
{
//printf("f is %p\n", f);
if (f is null)
return 0; // key not found, so AA's are not equal
if (key_hash == f.hash)
{
//printf("hash equals\n");
if (keyti.equals(pkey, f + 1))
{ // Found key in e2. Compare values
//printf("key equals\n");
auto pvalue2 = cast(void *)(f + 1) + keysize;
if (valueti.equals(pvalue, pvalue2))
{
//printf("value equals\n");
break;
}
else
return 0; // values don't match, so AA's are not equal
}
}
f = f.next;
}
// Look at next entry in e1
e = e.next;
} while (e !is null);
return 1; // this subtree matches
}
foreach (e; e1.impl.buckets)
{
if (e)
{ if (_aaKeys_x(e) == 0)
return 0;
}
}
return 1; // equal
}
/*****************************************
* Computes a hash value for the entire AA
* Returns:
* Hash value
*/
hash_t _aaGetHash(in AA* aa, in TypeInfo tiRaw) nothrow
{
import rt.util.hash;
if (aa.impl is null)
return 0;
hash_t h = 0;
const TypeInfo_AssociativeArray ti = _aaUnwrapTypeInfo(tiRaw);
const keyti = ti.key;
const valueti = ti.next;
const keysize = aligntsize(keyti.tsize);
foreach (const(Entry)* e; aa.impl.buckets)
{
while (e)
{
auto pkey = cast(void*)(e + 1);
auto pvalue = pkey + keysize;
// Compute a hash for the key/value pair by hashing their
// respective hash values.
hash_t[2] hpair;
hpair[0] = e.hash;
hpair[1] = valueti.getHash(pvalue);
// Combine the hash of the key/value pair with the running hash
// value using an associative operator (+) so that the resulting
// hash value is independent of the actual order the pairs are
// stored in (important to ensure equality of hash value for two
// AA's containing identical pairs but with different hashtable
// sizes).
h += hashOf(hpair.ptr, hpair.length * hash_t.sizeof);
e = e.next;
}
}
return h;
}
pure nothrow unittest
{
string[int] key1 = [1: "true", 2: "false"];
string[int] key2 = [1: "false", 2: "true"];
// AA lits create a larger hashtable
int[string[int]] aa1 = [key1: 100, key2: 200];
// Ensure consistent hash values are computed for key1
assert((key1 in aa1) !is null);
// Manually assigning to an empty AA creates a smaller hashtable
int[string[int]] aa2;
aa2[key1] = 100;
aa2[key2] = 200;
assert(aa1 == aa2);
// Ensure binary-independence of equal hash keys
string[int] key2a;
key2a[1] = "false";
key2a[2] = "true";
assert(aa1[key2a] == 200);
}
// Issue 9852
pure nothrow unittest
{
// Original test case (revised, original assert was wrong)
int[string] a;
a["foo"] = 0;
a.remove("foo");
assert(a == null); // should not crash
int[string] b;
assert(b is null);
assert(a == b); // should not deref null
assert(b == a); // ditto
int[string] c;
c["a"] = 1;
assert(a != c); // comparison with empty non-null AA
assert(c != a);
assert(b != c); // comparison with null AA
assert(c != b);
}
/**
* _aaRange implements a ForwardRange
*/
struct Range
{
Impl* impl;
Entry* current;
}
Range _aaRange(AA aa) pure nothrow @nogc
{
typeof(return) res;
if (aa.impl is null)
return res;
res.impl = aa.impl;
foreach (entry; aa.impl.buckets)
{
if (entry !is null)
{
res.current = entry;
break;
}
}
return res;
}
bool _aaRangeEmpty(Range r) pure nothrow @nogc
{
return r.current is null;
}
void* _aaRangeFrontKey(Range r) pure nothrow @nogc
in
{
assert(r.current !is null);
}
body
{
return cast(void*)r.current + Entry.sizeof;
}
void* _aaRangeFrontValue(Range r) pure nothrow @nogc
in
{
assert(r.current !is null);
assert(r.impl.keyti !is null); // set on first insert
}
body
{
return cast(void*)r.current + Entry.sizeof + aligntsize(r.impl.keyti.tsize);
}
void _aaRangePopFront(ref Range r) pure nothrow @nogc
{
if (r.current.next !is null)
{
r.current = r.current.next;
}
else
{
immutable idx = r.current.hash % r.impl.buckets.length;
r.current = null;
foreach (entry; r.impl.buckets[idx + 1 .. $])
{
if (entry !is null)
{
r.current = entry;
break;
}
}
}
}
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