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ircd:Ⓜ️:state: Make it right.

This commit is contained in:
Jason Volk 2018-02-02 14:57:50 -08:00
parent 50a0983fa0
commit 63d28a77cc
3 changed files with 167 additions and 168 deletions

View file

@ -60,6 +60,50 @@ namespace ircd::m::state::name
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wsubobject-linkage"
/// Format for node: Node is plaintext and not binary at this time. In fact,
/// *evil chuckle*, node might as well be JSON and can easily become content
/// of another event sent to other rooms over network *snorts*. (important:
/// database is well compressed).
///
/// { ;
/// "k": ; Key array
/// [ ;
/// ["m.room.member", "@ar4an:matrix.org"], ; Left key
/// ["m.room.member", "@jzk:matrix.org"] ; Right key
/// ], ;
/// "v": ; Value array
/// [ ;
/// "$14961836116kXQRA:matrix.org", ; Left accept
/// "$15018692261xPQDB:matrix.org", ; Right accept
/// ] ;
/// "c": ; Child array
/// [ ;
/// "nPKN9twTF9a8k5dD7AApFcaraHTX", ; Left child
/// "PcxAAACvkvyUMz19AZcCfrC3S84s", ; Center child
/// "2jVYKIMKErJ6w6BLMhfVjsXearhB", ; Right child
/// ] ;
/// } ;
///
/// Elements are ordered based on type+state_key lexical sort. The type
/// and the state_key strings are literally concatenated to this effect.
/// They're not hashed. We can have some more control over data locality
/// this way. Any number of values may be in a key array, not just type+
/// state_key. The concatenation involves the string with its surrounding
/// quotes as to not allow the user to mess about conflicting values.
/// ```
/// "m.room.member""@jzk" > "m.room.create"""
/// ```
/// Unlike traditional trees of such variety, the number of elements is not
/// really well defined and not even fixed. There just has to be one more
/// value in the "child" list than there are keys in the "key" list. To make
/// this structure efficient we have to figure out a good number of
/// children per node, and that might even be a contextual decision. The
/// more children, the less depth to the query, but at the cost of a larger
/// node size. A larger node in this system isn't just relevant to
/// retrieval, but consider nodes are also immutable. Changes to the tree
/// create new nodes for each changed path so the old nodes can still
/// represent the old state.
struct ircd::m::state::node
:json::tuple
<
@ -91,6 +135,28 @@ struct ircd::m::state::node
};
#pragma GCC diagnostic pop
struct ircd::m::state::node::rep
{
std::array<json::array, NODE_MAX_KEY + 1> keys;
std::array<string_view, NODE_MAX_VAL + 1> vals;
std::array<string_view, NODE_MAX_DEG + 1> chld;
size_t kn {0};
size_t vn {0};
size_t cn {0};
bool full() const;
bool overfull() const;
size_t find(const json::array &key) const;
void shr(const size_t &pos);
json::object write(const mutable_buffer &out);
string_view write(db::txn &, const mutable_buffer &id);
rep(const node &node);
rep() = default;
};
static_assert
(
ircd::m::state::NODE_MAX_KEY == ircd::m::state::NODE_MAX_VAL

View file

@ -10,122 +10,6 @@
#include <ircd/m/m.h>
struct ircd::m::state::node::rep
{
std::array<json::array, NODE_MAX_KEY + 1> keys;
std::array<string_view, NODE_MAX_VAL + 1> vals;
std::array<string_view, NODE_MAX_DEG + 1> chld;
size_t kn {0};
size_t vn {0};
size_t cn {0};
bool full() const;
bool overfull() const;
size_t find(const json::array &key) const;
void shr(const size_t &pos);
json::object write(const mutable_buffer &out);
string_view write(db::txn &, const mutable_buffer &id);
rep(const node &node);
rep() = default;
};
ircd::m::state::node::rep::rep(const node &node)
:kn{node.keys(keys.data(), keys.size())}
,vn{node.vals(vals.data(), vals.size())}
,cn{node.childs(chld.data(), chld.size())}
{
}
ircd::string_view
ircd::m::state::node::rep::write(db::txn &txn,
const mutable_buffer &idbuf)
{
thread_local char buf[NODE_MAX_SZ];
return set_node(txn, idbuf, write(buf));
}
ircd::json::object
ircd::m::state::node::rep::write(const mutable_buffer &out)
{
assert(kn == vn);
assert(cn <= kn + 1);
assert(kn > 0 && vn > 0);
assert(kn <= NODE_MAX_KEY);
assert(vn <= NODE_MAX_VAL);
assert(cn <= NODE_MAX_DEG);
json::value keys[kn];
{
for(size_t i(0); i < kn; ++i)
keys[i] = this->keys[i];
}
json::value vals[vn];
{
for(size_t i(0); i < vn; ++i)
vals[i] = this->vals[i];
};
json::value chld[cn];
{
for(size_t i(0); i < cn; ++i)
chld[i] = this->chld[i];
};
json::iov iov;
const json::iov::push push[]
{
{ iov, { "k"_sv, { keys, kn } } },
{ iov, { "v"_sv, { vals, vn } } },
{ iov, { "c"_sv, { chld, cn } } },
};
return { data(out), json::print(out, iov) };
}
/// Shift right.
void
ircd::m::state::node::rep::shr(const size_t &pos)
{
std::copy_backward(begin(keys) + pos, begin(keys) + kn, begin(keys) + kn + 1);
std::copy_backward(begin(vals) + pos, begin(vals) + vn, begin(vals) + vn + 1);
std::copy_backward(begin(chld) + pos, begin(chld) + cn, begin(chld) + cn + 1);
}
size_t
ircd::m::state::node::rep::find(const json::array &parts)
const
{
size_t i{0};
for(; i < kn; ++i)
if(keycmp(parts, keys[i]) <= 0)
return i;
else
++i;
return i;
}
bool
ircd::m::state::node::rep::overfull()
const
{
assert(kn == vn);
return kn > NODE_MAX_KEY;
}
bool
ircd::m::state::node::rep::full()
const
{
assert(kn == vn);
return kn >= NODE_MAX_KEY;
}
void
ircd::m::state::append_nodes(db::txn &txn,
const event &event)
@ -199,8 +83,6 @@ inserter(int8_t &height,
node::rep rep{node};
const auto pos{node.find(key)};
std::cout << int(height) << " " << pos << " " << node << " <---- " << key << std::endl;
if(keycmp(node.key(pos), key) == 0)
{
rep.keys[pos] = key;
@ -283,9 +165,6 @@ inserter(int8_t &height,
return rep.write(txn, idbuf);
}
std::cout << "INTEGRATE PUSH T: " << child_id << std::endl;
std::cout << "INTEGRATE PUSH U: " << node << std::endl;
rep.shr(pos);
rep.keys[pos] = key;
++rep.kn;
@ -575,6 +454,104 @@ ircd::m::state::keycmp(const json::array &a,
1;
}
//
// rep
//
ircd::m::state::node::rep::rep(const node &node)
:kn{node.keys(keys.data(), keys.size())}
,vn{node.vals(vals.data(), vals.size())}
,cn{node.childs(chld.data(), chld.size())}
{
}
ircd::string_view
ircd::m::state::node::rep::write(db::txn &txn,
const mutable_buffer &idbuf)
{
thread_local char buf[NODE_MAX_SZ];
return set_node(txn, idbuf, write(buf));
}
ircd::json::object
ircd::m::state::node::rep::write(const mutable_buffer &out)
{
assert(kn == vn);
assert(cn <= kn + 1);
assert(kn > 0 && vn > 0);
assert(kn <= NODE_MAX_KEY);
assert(vn <= NODE_MAX_VAL);
assert(cn <= NODE_MAX_DEG);
json::value keys[kn];
{
for(size_t i(0); i < kn; ++i)
keys[i] = this->keys[i];
}
json::value vals[vn];
{
for(size_t i(0); i < vn; ++i)
vals[i] = this->vals[i];
};
json::value chld[cn];
{
for(size_t i(0); i < cn; ++i)
chld[i] = this->chld[i];
};
json::iov iov;
const json::iov::push push[]
{
{ iov, { "k"_sv, { keys, kn } } },
{ iov, { "v"_sv, { vals, vn } } },
{ iov, { "c"_sv, { chld, cn } } },
};
return { data(out), json::print(out, iov) };
}
/// Shift right.
void
ircd::m::state::node::rep::shr(const size_t &pos)
{
std::copy_backward(begin(keys) + pos, begin(keys) + kn, begin(keys) + kn + 1);
std::copy_backward(begin(vals) + pos, begin(vals) + vn, begin(vals) + vn + 1);
std::copy_backward(begin(chld) + pos, begin(chld) + cn, begin(chld) + cn + 1);
}
size_t
ircd::m::state::node::rep::find(const json::array &parts)
const
{
size_t i{0};
for(; i < kn; ++i)
if(keycmp(parts, keys[i]) <= 0)
return i;
else
++i;
return i;
}
bool
ircd::m::state::node::rep::overfull()
const
{
assert(kn == vn);
return kn > NODE_MAX_KEY;
}
bool
ircd::m::state::node::rep::full()
const
{
assert(kn == vn);
return kn >= NODE_MAX_KEY;
}
//
// node
//
@ -605,8 +582,9 @@ const
/// and argument compares less than both, 0 is returned; equal to key[0],
/// 0 is returned; greater than key[0] and less than or equal to key[1],
/// 1 is returned; greater than both: 2 is returned. Note that there can
/// be one more vals() than keys() in a node (this is usually a "full node")
/// but there might not be, and the returned pos might be out of range.
/// be one more childs() than keys() in a node (this is usually a "full
/// node") but there might not be, and the returned pos might be out of
/// range.
size_t
ircd::m::state::node::find(const json::array &parts)
const

View file

@ -805,51 +805,6 @@ const database::description events_description
// (state tree node id) => (state tree node)
//
// Format for node: Node is plaintext and not binary at this time. In fact,
// *evil chuckle*, node might as well be JSON and can easily become content
// of another event sent to other rooms over network *snorts*. (important:
// database is well compressed).
//
// { ;
// "k": ; Key array
// [ ;
// ["m.room.member", "@ar4an"], ; Left key
// ["m.room.member", "@jzk"] ; Right key
// ], ;
// "v": ; Value array
// [ ;
// "$14961836116kXQRA:matrix.org", ; Left accept
// "$15018692261xPQDB:matrix.org", ; Right accept
// ] ;
// "c": ; Child array
// [ ;
// "nPKN9twTF9a8k5dD7AApFcaraHTX", ; Left child
// "PcxAAACvkvyUMz19AZcCfrC3S84s", ; Center child
// "2jVYKIMKErJ6w6BLMhfVjsXearhB", ; Right child
// ] ;
// } ;
//
// (note: actual JSON used is canonical and spaceless)
//
// Elements are ordered based on type+state_key lexical sort. The type
// and the state_key strings are literally concatenated to this effect.
// They're not hashed. We can have some more control over data locality
// this way. Any number of values may be in a key array, not just type+
// state_key. The concatenation involves the string with its surrounding
// quotes as to not allow the user to mess about conflicting values.
// ```
// "m.room.member""@jzk" > "m.room.create"""
// ```
// Unlike traditional trees of such variety, the number of elements is not
// really well defined and not even fixed. There just has to be one more
// value in the "child" list than there are keys in the "key" list. To make
// this structure efficient we have to figure out a good number of
// children per node, and that might even be a contextual decision. The
// more children, the less depth to the query, but at the cost of a larger
// node size. A larger node in this system isn't just relevant to
// retrieval, but consider nodes are also immutable. Changes to the tree
// create new nodes for each changed path so the old nodes can still
// represent the old state.
state_node,
};