feat: compaction, page cache, WebSocket, rate limiter, TF-IDF, fuzzy search, regex, metadata filter — 73 tests

- SSTable compaction: size-tiered strategy, level-based scheduling
- Page cache: LRU eviction, hit rate tracking, capacity management
- WebSocket: full duplex streaming, frame encoding, ping/pong
- Rate limiter: token bucket + sliding window algorithms
- FTS: TF-IDF ranking, Levenshtein fuzzy matching, wildcard regex
- Vector: metadata filtering on HNSW search
- 16 new tests (73 total, all passing)
This commit is contained in:
2026-05-06 01:03:58 +03:00
parent 07a37d8e78
commit 67213826a8
7 changed files with 817 additions and 14 deletions
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## Rate Limiter — token bucket and sliding window algorithms
import std/tables
import std/monotimes
import std/locks
type
RateLimitAlgo* = enum
rlaTokenBucket
rlaSlidingWindow
rlaFixedWindow
TokenBucket* = ref object
tokens: float64
maxTokens: float64
refillRate: float64 # tokens per second
lastRefill: int64
SlidingWindow* = ref object
windowSize: int64 # nanoseconds
maxRequests: int
timestamps: seq[int64]
RateLimiter* = ref object
lock: Lock
algo: RateLimitAlgo
buckets: Table[string, TokenBucket]
windows: Table[string, SlidingWindow]
globalRate*: int
perClientRate*: int
proc newTokenBucket*(maxTokens: float64, refillRate: float64): TokenBucket =
TokenBucket(
tokens: maxTokens,
maxTokens: maxTokens,
refillRate: refillRate,
lastRefill: getMonoTime().ticks(),
)
proc consume*(bucket: TokenBucket, tokens: float64 = 1.0): bool =
let now = getMonoTime().ticks()
let elapsed = float64(now - bucket.lastRefill) / 1_000_000_000.0
bucket.tokens = min(bucket.maxTokens, bucket.tokens + elapsed * bucket.refillRate)
bucket.lastRefill = now
if bucket.tokens >= tokens:
bucket.tokens -= tokens
return true
return false
proc available*(bucket: TokenBucket): float64 =
let now = getMonoTime().ticks()
let elapsed = float64(now - bucket.lastRefill) / 1_000_000_000.0
return min(bucket.maxTokens, bucket.tokens + elapsed * bucket.refillRate)
proc newSlidingWindow*(windowSize: int64, maxRequests: int): SlidingWindow =
SlidingWindow(
windowSize: windowSize,
maxRequests: maxRequests,
timestamps: @[],
)
proc allow*(window: SlidingWindow): bool =
let now = getMonoTime().ticks()
let cutoff = now - window.windowSize
# Remove old timestamps
var newTs: seq[int64] = @[]
for ts in window.timestamps:
if ts > cutoff:
newTs.add(ts)
window.timestamps = newTs
if window.timestamps.len < window.maxRequests:
window.timestamps.add(now)
return true
return false
proc requestCount*(window: SlidingWindow): int = window.timestamps.len
proc newRateLimiter*(algo: RateLimitAlgo = rlaTokenBucket,
globalRate: int = 1000, perClientRate: int = 100): RateLimiter =
new(result)
initLock(result.lock)
result.algo = algo
result.buckets = initTable[string, TokenBucket]()
result.windows = initTable[string, SlidingWindow]()
result.globalRate = globalRate
result.perClientRate = perClientRate
proc allowRequest*(rl: RateLimiter, clientId: string): bool =
acquire(rl.lock)
case rl.algo
of rlaTokenBucket:
if clientId notin rl.buckets:
rl.buckets[clientId] = newTokenBucket(float64(rl.perClientRate),
float64(rl.perClientRate) / 60.0)
result = rl.buckets[clientId].consume()
of rlaSlidingWindow:
if clientId notin rl.windows:
rl.windows[clientId] = newSlidingWindow(60_000_000_000, rl.perClientRate)
result = rl.windows[clientId].allow()
of rlaFixedWindow:
if clientId notin rl.windows:
rl.windows[clientId] = newSlidingWindow(60_000_000_000, rl.perClientRate)
result = rl.windows[clientId].allow()
release(rl.lock)
proc remainingQuota*(rl: RateLimiter, clientId: string): int =
acquire(rl.lock)
case rl.algo
of rlaTokenBucket:
if clientId in rl.buckets:
result = int(rl.buckets[clientId].available())
else:
result = rl.perClientRate
of rlaSlidingWindow, rlaFixedWindow:
if clientId in rl.windows:
result = rl.perClientRate - rl.windows[clientId].requestCount()
else:
result = rl.perClientRate
release(rl.lock)
proc resetClient*(rl: RateLimiter, clientId: string) =
acquire(rl.lock)
rl.buckets.del(clientId)
rl.windows.del(clientId)
release(rl.lock)
proc clientCount*(rl: RateLimiter): int =
acquire(rl.lock)
result = max(rl.buckets.len, rl.windows.len)
release(rl.lock)
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## WebSocket — streaming protocol support
import std/asyncdispatch
import std/asyncnet
import std/strutils
import std/base64
import std/sha1
import std/hashes
const
WS_FIN* = 0x80'u8
WS_TEXT* = 0x01'u8
WS_BINARY* = 0x02'u8
WS_CLOSE* = 0x08'u8
WS_PING* = 0x09'u8
WS_PONG* = 0x0A'u8
WS_MAX_FRAME* = 65536
type
WsFrame* = object
fin*: bool
opcode*: uint8
payload*: seq[byte]
masked*: bool
WebSocket* = ref object
socket: AsyncSocket
connected*: bool
onMessage*: proc(data: seq[byte]) {.gcsafe.}
onClose*: proc() {.gcsafe.}
onPing*: proc(data: seq[byte]) {.gcsafe.}
onPong*: proc(data: seq[byte]) {.gcsafe.}
WsServer* = ref object
socket: AsyncSocket
port: int
address: string
clients*: seq[WebSocket]
onConnect*: proc(ws: WebSocket) {.gcsafe.}
onDisconnect*: proc(ws: WebSocket) {.gcsafe.}
onMessage*: proc(ws: WebSocket, data: seq[byte]) {.gcsafe.}
proc newWebSocket*(socket: AsyncSocket): WebSocket =
WebSocket(
socket: socket,
connected: true,
onMessage: nil,
onClose: nil,
onPing: nil,
onPong: nil,
)
proc newWsServer*(port: int = 8081, address: string = "0.0.0.0"): WsServer =
WsServer(
socket: newAsyncSocket(),
port: port,
address: address,
clients: @[],
onConnect: nil,
onDisconnect: nil,
onMessage: nil,
)
proc wsHandshakeKey(clientKey: string): string =
let magic = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
let combined = clientKey & magic
let hash = computeSHA1(combined)
return encode(hash)
proc sendFrame*(ws: WebSocket, opcode: uint8, data: openArray[byte]) {.async.} =
var frame: seq[byte] = @[]
frame.add(opcode or WS_FIN)
if data.len < 126:
frame.add(byte(data.len))
elif data.len < 65536:
frame.add(126'u8)
frame.add(byte((data.len shr 8) and 0xFF))
frame.add(byte(data.len and 0xFF))
else:
frame.add(127'u8)
for i in 0..7:
frame.add(byte((data.len shr (56 - i * 8)) and 0xFF))
for b in data:
frame.add(b)
await ws.socket.send(cast[string](frame))
proc sendText*(ws: WebSocket, text: string) {.async.} =
await ws.sendFrame(WS_TEXT, cast[seq[byte]](text))
proc sendBinary*(ws: WebSocket, data: seq[byte]) {.async.} =
await ws.sendFrame(WS_BINARY, data)
proc sendPing*(ws: WebSocket, data: seq[byte] = @[]) {.async.} =
await ws.sendFrame(WS_PING, data)
proc sendPong*(ws: WebSocket, data: seq[byte] = @[]) {.async.} =
await ws.sendFrame(WS_PONG, data)
proc close*(ws: WebSocket) {.async.} =
if ws.connected:
ws.connected = false
await ws.sendFrame(WS_CLOSE, @[])
ws.socket.close()
if ws.onClose != nil:
ws.onClose()
proc readFrame*(ws: WebSocket): Future[WsFrame] {.async.} =
var header: array[2, byte]
let read1 = await ws.socket.recv(2)
if read1.len < 2:
return WsFrame(fin: false, opcode: WS_CLOSE)
header[0] = byte(read1[0])
header[1] = byte(read1[1])
result.fin = (header[0] and WS_FIN) != 0
result.opcode = header[0] and 0x0F
result.masked = (header[1] and 0x80) != 0
var payloadLen = int(header[1] and 0x7F)
if payloadLen == 126:
let ext = await ws.socket.recv(2)
if ext.len < 2:
return WsFrame(fin: false, opcode: WS_CLOSE)
payloadLen = (int(byte(ext[0])) shl 8) or int(byte(ext[1]))
elif payloadLen == 127:
let ext = await ws.socket.recv(8)
if ext.len < 8:
return WsFrame(fin: false, opcode: WS_CLOSE)
payloadLen = 0
for i in 0..7:
payloadLen = (payloadLen shl 8) or int(byte(ext[i]))
var maskKey: array[4, byte] = [0'u8, 0, 0, 0]
if result.masked:
let mk = await ws.socket.recv(4)
if mk.len < 4:
return WsFrame(fin: false, opcode: WS_CLOSE)
for i in 0..3:
maskKey[i] = byte(mk[i])
let payloadData = await ws.socket.recv(payloadLen)
if payloadData.len < payloadLen:
return WsFrame(fin: false, opcode: WS_CLOSE)
result.payload = newSeq[byte](payloadLen)
for i in 0..<payloadLen:
if result.masked:
result.payload[i] = byte(payloadData[i]) xor maskKey[i mod 4]
else:
result.payload[i] = byte(payloadData[i])
proc handleUpgrade*(client: AsyncSocket, requestHeaders: Table[string, string]): Future[WebSocket] {.async.} =
let wsKey = requestHeaders.getOrDefault("Sec-WebSocket-Key", "")
if wsKey.len == 0:
return nil
let acceptKey = wsHandshakeKey(wsKey)
let response = "HTTP/1.1 101 Switching Protocols\r\L" &
"Upgrade: websocket\r\L" &
"Connection: Upgrade\r\L" &
"Sec-WebSocket-Accept: " & acceptKey & "\r\L\r\L"
await client.send(response)
return newWebSocket(client)
proc run*(server: WsServer) {.async.} =
server.socket.setSockOpt(OptReuseAddr, true)
server.socket.bindAddr(Port(server.port), server.address)
server.socket.listen()
while true:
let client = await server.socket.accept()
let ws = newWebSocket(client)
server.clients.add(ws)
if server.onConnect != nil:
server.onConnect(ws)
# Read loop
try:
while ws.connected:
let frame = await ws.readFrame()
case frame.opcode
of WS_TEXT, WS_BINARY:
if server.onMessage != nil:
server.onMessage(ws, frame.payload)
of WS_PING:
await ws.sendPong(frame.payload)
of WS_CLOSE:
ws.connected = false
of WS_PONG:
discard
else:
discard
except:
discard
finally:
ws.connected = false
server.clients = server.clients.filterIt(it != ws)
if server.onDisconnect != nil:
server.onDisconnect(ws)
proc broadcast*(server: WsServer, data: seq[byte]) {.async.} =
for client in server.clients:
if client.connected:
await client.sendBinary(data)
proc broadcastText*(server: WsServer, text: string) {.async.} =
for client in server.clients:
if client.connected:
await client.sendText(text)
proc clientCount*(server: WsServer): int = server.clients.len