blob: a0f338ad93113ffdfd641aa3d0760623a92ddb91 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
|
// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
#pragma once
#include "entry_comparator.h"
#include "unique_store_string_allocator.h"
#include <vespa/vespalib/stllike/hash_fun.h>
namespace vespalib::datastore {
/**
* Compare two strings based on entry refs.
*
* Valid entry ref is mapped to a string in a data store.
* Invalid entry ref is mapped to a temporary string pointed to by comparator instance.
*/
template <typename RefT>
class UniqueStoreStringComparator : public EntryComparator {
protected:
using RefType = RefT;
using WrappedExternalEntryType = UniqueStoreEntry<std::string>;
using DataStoreType = DataStoreT<RefT>;
const DataStoreType &_store;
const char *_lookup_value;
const char *get(EntryRef ref) const {
if (ref.valid()) {
RefType iRef(ref);
const auto &meta = _store.getBufferMeta(iRef.bufferId());
auto type_id = meta.getTypeId();
if (type_id != 0) {
return reinterpret_cast<const UniqueStoreSmallStringEntry *>(_store.template getEntryArray<char>(iRef, meta.get_array_size()))->value();
} else {
return _store.template getEntry<WrappedExternalEntryType>(iRef)->value().c_str();
}
} else {
return _lookup_value;
}
}
UniqueStoreStringComparator(const DataStoreType &store, const char *lookup_value)
: _store(store),
_lookup_value(lookup_value)
{
}
public:
UniqueStoreStringComparator(const DataStoreType &store)
: _store(store),
_lookup_value(nullptr)
{
}
bool less(const EntryRef lhs, const EntryRef rhs) const override {
const char *lhs_value = get(lhs);
const char *rhs_value = get(rhs);
return (strcmp(lhs_value, rhs_value) < 0);
}
bool equal(const EntryRef lhs, const EntryRef rhs) const override {
const char *lhs_value = get(lhs);
const char *rhs_value = get(rhs);
return (strcmp(lhs_value, rhs_value) == 0);
}
size_t hash(const EntryRef rhs) const override {
const char *rhs_value = get(rhs);
vespalib::hash<const char *> hasher;
return hasher(rhs_value);
}
UniqueStoreStringComparator<RefT> make_for_lookup(const char* lookup_value) const {
return UniqueStoreStringComparator<RefT>(_store, lookup_value);
}
};
}
|
