Martchus
/
lmdb-safe
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Use type alias for ID type

This commit is contained in:
Martchus 2022-02-21 22:57:15 +01:00
parent b87dd49bba
commit 6c21fe7cb1
2 changed files with 26 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
lmdb-typed.cc
View File

@ -2,13 +2,13 @@
namespace LMDBSafe {
unsigned int MDBGetMaxID(MDBRWTransaction &txn, MDBDbi &dbi)
IDType MDBGetMaxID(MDBRWTransaction &txn, MDBDbi &dbi)
{
auto cursor = txn->getRWCursor(dbi);
MDBOutVal maxidval, maxcontent;
unsigned int maxid{ 0 };
auto maxid = IDType(0);
if (!cursor.get(maxidval, maxcontent, MDB_LAST)) {
maxid = maxidval.get<unsigned int>();
maxid = maxidval.get<IDType>();
}
return maxid;
}

45
lmdb-typed.hh
View File

@ -10,20 +10,21 @@ namespace LMDBSafe {
/*
Open issues:
What is an error? What is an exception?
could id=0 be magic? ('no such id')
yes
Perhaps use the separate index concept from multi_index
perhaps get eiter to be of same type so for(auto& a : x) works
make it more value "like" with unique_ptr
*/
/*!
* \brief The type used to store IDs. "0" indicates "no such ID".
*/
using IDType = std::uint32_t;
/** Return the highest ID used in a database. Returns 0 for an empty DB.
This makes us start everything at ID=1, which might make it possible to
treat id 0 as special
*/
LMDB_SAFE_EXPORT unsigned int MDBGetMaxID(MDBRWTransaction &txn, MDBDbi &dbi);
LMDB_SAFE_EXPORT IDType MDBGetMaxID(MDBRWTransaction &txn, MDBDbi &dbi);
/** This is the serialization interface.
You need to define your these functions for the types you'd like to store.
@ -142,12 +143,12 @@ template <class Class, typename Type, typename Parent> struct LMDB_SAFE_EXPORT L
: d_parent(parent)
{
}
void put(MDBRWTransaction &txn, const Class &t, std::uint32_t id, unsigned int flags = 0)
void put(MDBRWTransaction &txn, const Class &t, IDType id, unsigned int flags = 0)
{
txn->put(d_idx, keyConv(d_parent->getMember(t)), id, flags);
}
void del(MDBRWTransaction &txn, const Class &t, std::uint32_t id)
void del(MDBRWTransaction &txn, const Class &t, IDType id)
{
if (const auto rc = txn->del(d_idx, keyConv(d_parent->getMember(t)), id)) {
throw LMDBError("Error deleting from index: ", rc);
@ -273,7 +274,7 @@ public:
}
//! Get item with id, from main table directly
bool get(std::uint32_t id, T &t)
bool get(IDType id, T &t)
{
MDBOutVal data;
if ((*d_parent.d_txn)->get(d_parent.d_parent->d_main, id, data))
@ -284,23 +285,23 @@ public:
}
//! Get item through index N, then via the main database
template <std::size_t N> std::uint32_t get(const index_t<N> &key, T &out)
template <std::size_t N> IDType get(const index_t<N> &key, T &out)
{
MDBOutVal id;
if (!(*d_parent.d_txn)->get(std::get<N>(d_parent.d_parent->d_tuple).d_idx, keyConv(key), id)) {
if (get(id.get<std::uint32_t>(), out))
return id.get<std::uint32_t>();
if (get(id.get<IDType>(), out))
return id.get<IDType>();
}
return 0;
}
//! Cardinality of index N
template <std::size_t N> std::uint32_t cardinality()
template <std::size_t N> IDType cardinality()
{
auto cursor = (*d_parent.d_txn)->getCursor(std::get<N>(d_parent.d_parent->d_tuple).d_idx);
bool first = true;
MDBOutVal key, data;
std::uint32_t count = 0;
IDType count = 0;
while (!cursor.get(key, data, first ? MDB_FIRST : MDB_NEXT_NODUP)) {
++count;
first = false;
@ -463,9 +464,9 @@ public:
}
// get ID this iterator points to
std::uint32_t getID()
IDType getID()
{
return d_on_index ? d_id.get<std::uint32_t>() : d_key.get<std::uint32_t>();
return d_on_index ? d_id.get<IDType>() : d_key.get<IDType>();
}
const MDBOutVal &getKey()
@ -526,7 +527,7 @@ public:
return iter_t<StorageType>{ &d_parent, std::move(cursor), false, false };
};
template <std::size_t N, template <typename> class StorageType = DirectStorage> iter_t<DirectStorage, std::uint32_t> begin_idx()
template <std::size_t N, template <typename> class StorageType = DirectStorage> iter_t<DirectStorage, IDType> begin_idx()
{
typename Parent::cursor_t cursor = (*d_parent.d_txn)->getCursor(std::get<N>(d_parent.d_parent->d_tuple).d_idx);
@ -534,10 +535,10 @@ public:
if (cursor.get(out, id, MDB_FIRST)) {
// on_index, one_key, end
return iter_t<DirectStorage, std::uint32_t>{ &d_parent, std::move(cursor), false, false, true };
return iter_t<DirectStorage, IDType>{ &d_parent, std::move(cursor), false, false, true };
}
return iter_t<DirectStorage, std::uint32_t>{ &d_parent, std::move(cursor), false, false };
return iter_t<DirectStorage, IDType>{ &d_parent, std::move(cursor), false, false };
}
eiter_t end()
@ -721,7 +722,7 @@ public:
}
// insert something, with possibly a specific id
std::uint32_t put(const T &t, std::uint32_t id = 0)
IDType put(const T &t, IDType id = 0)
{
unsigned int flags = 0;
if (!id) {
@ -734,7 +735,7 @@ public:
}
// modify an item 'in place', plus update indexes
void modify(std::uint32_t id, std::function<void(T &)> func)
void modify(IDType id, std::function<void(T &)> func)
{
T t;
if (!this->get(id, t))
@ -746,7 +747,7 @@ public:
}
//! delete an item, and from indexes
void del(std::uint32_t id)
void del(IDType id)
{
T t;
if (!this->get(id, t))
@ -786,7 +787,7 @@ public:
private:
// clear this ID from all indexes
void clearIndex(std::uint32_t id, const T &t)
void clearIndex(IDType id, const T &t)
{
d_parent->forEachIndex([&](auto &&i) { i.del(*d_txn, t, id); });
}