janiussyafiq commented on code in PR #13578: URL: https://github.com/apache/apisix/pull/13578#discussion_r3458073422
########## apisix/plugins/ai-cache/schema.lua: ########## @@ -0,0 +1,95 @@ +-- +-- Licensed to the Apache Software Foundation (ASF) under one or more +-- contributor license agreements. See the NOTICE file distributed with +-- this work for additional information regarding copyright ownership. +-- The ASF licenses this file to You under the Apache License, Version 2.0 +-- (the "License"); you may not use this file except in compliance with +-- the License. You may obtain a copy of the License at +-- +-- http://www.apache.org/licenses/LICENSE-2.0 +-- +-- Unless required by applicable law or agreed to in writing, software +-- distributed under the License is distributed on an "AS IS" BASIS, +-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +-- See the License for the specific language governing permissions and +-- limitations under the License. +-- + +local core = require("apisix.core") +local redis_schema = require("apisix.utils.redis-schema") + +local policy_to_additional_properties = core.table.deepcopy(redis_schema.schema) + +local _M = { + type = "object", + properties = { + layers = { Review Comment: dropped the knob until L2 ########## apisix/plugins/ai-cache.lua: ########## @@ -0,0 +1,199 @@ +-- +-- Licensed to the Apache Software Foundation (ASF) under one or more +-- contributor license agreements. See the NOTICE file distributed with +-- this work for additional information regarding copyright ownership. +-- The ASF licenses this file to You under the Apache License, Version 2.0 +-- (the "License"); you may not use this file except in compliance with +-- the License. You may obtain a copy of the License at +-- +-- http://www.apache.org/licenses/LICENSE-2.0 +-- +-- Unless required by applicable law or agreed to in writing, software +-- distributed under the License is distributed on an "AS IS" BASIS, +-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +-- See the License for the specific language governing permissions and +-- limitations under the License. +-- + +local core = require("apisix.core") +local schema = require("apisix.plugins.ai-cache.schema") +local key_mod = require("apisix.plugins.ai-cache.key") +local redis_util = require("apisix.utils.redis") + +local ngx = ngx +local ngx_null = ngx.null +local ipairs = ipairs +local concat = table.concat + +local CACHE_STATUS_HEADER = "X-AI-Cache-Status" +local CACHE_AGE_HEADER = "X-AI-Cache-Age" +local DEFAULT_TTL = 3600 +local DEFAULT_MAX_BODY = 1048576 + +local _M = { + version = 0.1, + priority = 1035, + name = "ai-cache", + schema = schema, +} + + +function _M.check_schema(conf) + return core.schema.check(schema, conf) +end + + +local function release(conf, red) + local ok, err = red:set_keepalive(conf.redis_keepalive_timeout or 10000, + conf.redis_keepalive_pool or 100) + if not ok then + core.log.warn("ai-cache: failed to set redis keepalive: ", err) + end +end + + +local function serve_hit(conf, ctx, cached) + ctx.ai_cache_status = "HIT" + if conf.cache_headers ~= false then + core.response.set_header(CACHE_STATUS_HEADER, "HIT") + local age = ngx.time() - (cached.created_at or ngx.time()) + core.response.set_header(CACHE_AGE_HEADER, age < 0 and 0 or age) + end + core.response.set_header("Content-Type", "application/json") + return core.response.exit(200, cached.body) +end + + +function _M.access(conf, ctx) + -- Streaming responses are not cached in PR-1 (SSE replay is a later + -- increment). ai-proxy (higher priority) has already classified the + -- request, so bypass before doing any work. + if ctx.var.request_type == "ai_stream" then + ctx.ai_cache_status = "BYPASS" + return + end + + if conf.bypass_on then + for _, rule in ipairs(conf.bypass_on) do + if core.request.header(ctx, rule.header) == rule.equals then + ctx.ai_cache_status = "BYPASS" + return + end + end + end + + local body, err = core.request.get_json_request_body_table() + if not body then + core.log.warn("ai-cache: cannot read request body, bypassing: ", err) + ctx.ai_cache_status = "BYPASS" + return + end + + ctx.ai_cache_key = "ai-cache:l1:" .. key_mod.scope(conf, ctx) + .. ":" .. key_mod.fingerprint(ctx, body) + + local red + red, err = redis_util.new(conf) + if not red then + -- fail-open: never let a cache-backend outage break the request. + core.log.warn("ai-cache: redis unavailable, fail-open as MISS: ", err) + ctx.ai_cache_status = "MISS" + return + end + + local res + res, err = red:get(ctx.ai_cache_key) + release(conf, red) + if err then + core.log.warn("ai-cache: redis get failed, fail-open as MISS: ", err) + ctx.ai_cache_status = "MISS" + return + end + + if res ~= nil and res ~= ngx_null then + local cached = core.json.decode(res) + if cached and cached.body then + return serve_hit(conf, ctx, cached) + end + core.log.warn("ai-cache: discarding malformed cache entry for ", ctx.ai_cache_key) + end + + ctx.ai_cache_status = "MISS" +end + + +function _M.header_filter(conf, ctx) + if ctx.ai_cache_status and conf.cache_headers ~= false then + core.response.set_header(CACHE_STATUS_HEADER, ctx.ai_cache_status) + end +end + + +function _M.body_filter(conf, ctx) + -- only a MISS gets written back; HIT exited in access, BYPASS opts out. + if ctx.ai_cache_status ~= "MISS" or ctx.ai_cache_oversized then + return + end + local chunk = ngx.arg[1] + if chunk and #chunk > 0 then + local buf = ctx.ai_cache_buf + if not buf then + buf = { n = 0, bytes = 0 } + ctx.ai_cache_buf = buf + end + local n = buf.n + 1 + buf.n = n + buf[n] = chunk + buf.bytes = buf.bytes + #chunk + if buf.bytes > (conf.max_cache_body_size or DEFAULT_MAX_BODY) then + ctx.ai_cache_buf = nil + ctx.ai_cache_oversized = true + end + end +end + + +-- The response-capturing phases (body_filter / log) run in contexts where +-- cosockets are disabled, so the Redis write is deferred to a 0-delay timer +-- (timers run in a light thread where cosockets are allowed). +local function write_to_cache(premature, conf, cache_key, response_body) + if premature then + return + end + local red, err = redis_util.new(conf) + if not red then + core.log.warn("ai-cache: redis unavailable on write: ", err) + return + end + local envelope = core.json.encode({ body = response_body, created_at = ngx.time() }) + local ttl = (conf.exact and conf.exact.ttl) or DEFAULT_TTL + local ok + ok, err = red:set(cache_key, envelope, "EX", ttl) + if not ok then + core.log.warn("ai-cache: redis set failed: ", err) + end + release(conf, red) Review Comment: fixed -- This is an automated message from the Apache Git Service. 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