feat(ai): support configurable request JSON library

Makefile

@@ -137,6 +137,7 @@ deps: install-runtime
 		$(ENV_LUAROCKS) config $(ENV_LUAROCKS_FLAG_LOCAL) variables.OPENSSL_INCDIR $(addprefix $(ENV_OPENSSL_PREFIX), /include); \
 		$(ENV_LUAROCKS) config $(ENV_LUAROCKS_FLAG_LOCAL) variables.YAML_DIR $(ENV_LIBYAML_INSTALL_PREFIX); \
 		$(ENV_LUAROCKS) install apisix-master-0.rockspec --tree deps --only-deps $(ENV_LUAROCKS_SERVER_OPT); \
+		./utils/install-lua-resty-simdjson.sh deps; \
 	else \
 		$(call func_echo_warn_status, "WARNING: You're not using LuaRocks 3.x; please remove the luarocks and reinstall it via https://raw.githubusercontent.com/apache/apisix/master/utils/linux-install-luarocks.sh"); \
 		exit 1; \

apisix-master-0.rockspec

@@ -86,6 +86,7 @@ dependencies = {
     "api7-lua-resty-aws == 2.0.2-1",
     "multipart = 0.5.11-1",
     "luautf8 = 0.2.0-1",
+    "lua-qjson = 0.1.0-1",
 }
 
 build = {

apisix/cli/config.lua

@@ -29,6 +29,7 @@ local _M = {
     enable_server_tokens = true,
     extra_lua_path = "",
     extra_lua_cpath = "",
+    request_body_json_lib = "qjson",
     proxy_cache = {
       cache_ttl = "10s",
       zones = {

apisix/cli/schema.lua

@@ -92,6 +92,10 @@ local config_schema = {
                         },
                     }
                 },
+                request_body_json_lib = {
+                    enum = {"cjson", "simdjson", "qjson"},
+                    default = "qjson",
+                },
                 proxy_cache = {
                     type = "object",
                     properties = {

apisix/core/request.lua

@@ -21,7 +21,7 @@
 
 local lfs = require("lfs")
 local log = require("apisix.core.log")
-local json = require("apisix.core.json")
+local request_json = require("apisix.core.request_json")
 local io = require("apisix.core.io")
 local multipart = require("multipart")
 local core_str = require("apisix.core.string")
@@ -371,7 +371,7 @@ local function get_request_body_table(ctx, content_type)
         if not body then
             return nil, "could not get body: " .. (body_err or "request body is empty")
         end
-        result, err = json.decode(body)
+        result, err = request_json.decode(body)
         if not result then
             return nil, "could not parse JSON request body: " .. (err or "invalid JSON")
         end

apisix/core/request_json.lua

@@ -0,0 +1,172 @@
+--
+-- 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 config_local = require("apisix.core.config_local")
+local log = require("apisix.core.log")
+local core_json = require("apisix.core.json")
+local require = require
+local pcall = pcall
+
+
+local DEFAULT_JSON_LIB = "qjson"
+local json_libs = {
+    cjson = true,
+    qjson = true,
+    simdjson = true,
+}
+
+local qjson
+local simdjson_parser
+local qjson_unavailable
+local simdjson_unavailable
+local configured_name
+local warned_invalid_json_lib
+local warned_load_failure = {}
+
+local _M = {}
+
+
+local function configured_json_lib()
+    if configured_name then
+        return configured_name
+    end
+
+    local local_conf = config_local.local_conf()
+    local name = local_conf and local_conf.apisix
+                 and local_conf.apisix.request_body_json_lib
+                 or DEFAULT_JSON_LIB
+
+    if not json_libs[name] then
+        if not warned_invalid_json_lib then
+            warned_invalid_json_lib = true
+            log.warn("invalid apisix.request_body_json_lib: ", name,
+                     ", fallback to ", DEFAULT_JSON_LIB)
+        end
+        name = DEFAULT_JSON_LIB
+    end
+
+    configured_name = name
+    return configured_name
+end
+
+
+local function normalize_result(ok, res, err)
+    if not ok then
+        return nil, res
+    end
+
+    return res, err
+end
+
+
+local function qjson_module()
+    if qjson then
+        return qjson
+    end
+
+    if qjson_unavailable then
+        return nil, qjson_unavailable
+    end
+
+    local ok, mod = pcall(require, "qjson")
+    if not ok then
+        qjson_unavailable = "failed to load qjson: " .. mod
+        return nil, qjson_unavailable
+    end
+
+    qjson = mod
+    return qjson
+end
+
+
+local function warn_load_failure(name, err)
+    if warned_load_failure[name] then
+        return
+    end
+
+    warned_load_failure[name] = true
+    log.warn(err, ", fallback to cjson")
+end
+
+
+local function simdjson_decode(str)
+    if simdjson_unavailable then
+        return nil, simdjson_unavailable, true
+    end
+
+    if not simdjson_parser then
+        local ok, simdjson = pcall(require, "resty.simdjson")
+        if not ok then
+            simdjson_unavailable = "failed to load simdjson: " .. simdjson
+            return nil, simdjson_unavailable, true
+        end
+
+        local parser, err = simdjson.new()
+        if not parser then
+            simdjson_unavailable = "failed to create simdjson parser: "
+                                  .. (err or "unknown")
+            return nil, simdjson_unavailable, true
+        end
+        simdjson_parser = parser
+    end
+
+    return normalize_result(pcall(simdjson_parser.decode, simdjson_parser, str))
+end
+
+
+function _M.decode(str)
+    local name = configured_json_lib()
+    if name == "cjson" then
+        return core_json.decode(str)
+    end
+
+    if name == "simdjson" then
+        local res, err, can_fallback = simdjson_decode(str)
+        if can_fallback then
+            warn_load_failure(name, err)
+            return core_json.decode(str)
+        end
+
+        return res, err
+    end
+
+    local mod, err = qjson_module()
+    if not mod then
+        warn_load_failure(name, err)
+        return core_json.decode(str)
+    end
+
+    return normalize_result(pcall(mod.decode, str))
+end
+
+
+function _M.encode(data)
+    if configured_json_lib() == "qjson" then
+        local mod, err = qjson_module()
+        if not mod then
+            warn_load_failure("qjson", err)
+            return normalize_result(pcall(core_json.encode, data))
+        end
+
+        return normalize_result(pcall(mod.encode, data))
+    end
+
+    return normalize_result(pcall(core_json.encode, data))
+end
+
+
+return _M

apisix/plugins/ai-transport/auth-aws.lua

@@ -20,7 +20,7 @@
 
 require("resty.aws.config")  -- reads env vars before init
 local aws = require("resty.aws")
-local core = require("apisix.core")
+local request_json = require("apisix.core.request_json")
 local signer = require("resty.aws.request.sign")
 local ngx = ngx
 local ngx_escape_uri = ngx.escape_uri
@@ -81,7 +81,7 @@ function _M.sign_request(params, aws_conf, region)
 
     -- Serialize body to JSON string (SigV4 signs the exact bytes)
     if type(params.body) == "table" then
-        local body_str, err = core.json.encode(params.body)
+        local body_str, err = request_json.encode(params.body)
         if not body_str then
             return "failed to encode body: " .. (err or "")
         end

apisix/plugins/ai-transport/http.lua

@@ -19,6 +19,7 @@
 -- Provides HTTP client lifecycle management for AI provider requests.
 
 local core = require("apisix.core")
+local request_json = require("apisix.core.request_json")
 local http = require("resty.http")
 local ngx_now = ngx.now
 local pairs = pairs
@@ -107,7 +108,7 @@ function _M.request(params, timeout)
         req_json = params.body
     else
         local err
-        req_json, err = core.json.encode(params.body)
+        req_json, err = request_json.encode(params.body)
         if not req_json then
             httpc:close()
             return nil, "encode body: " .. (err or "unknown"), {

ci/common.sh

@@ -175,15 +175,64 @@ set_coredns() {
 
 GRPC_SERVER_EXAMPLE_VER=20210819
 
+rustc_meets_minimum_version () {
+    if ! command -v rustc >/dev/null 2>&1; then
+        return 1
+    fi
+
+    local version major minor
+    version=$(rustc --version | awk '{print $2}')
+    major=${version%%.*}
+    minor=${version#*.}
+    minor=${minor%%.*}
+
+    [ "$major" -gt 1 ] || { [ "$major" -eq 1 ] && [ "$minor" -ge 77 ]; }
+}
+
+install_recent_rust_toolchain () {
+    if rustc_meets_minimum_version; then
+        return
+    fi
+
+    local version target checksum tmp_dir tmp
+    version="${RUSTUP_INIT_VERSION:-1.28.2}"
+    case "$(uname -m)" in
+        x86_64|amd64)
+            target="x86_64-unknown-linux-gnu"
+            checksum="20a06e644b0d9bd2fbdbfd52d42540bdde820ea7df86e92e533c073da0cdd43c"
+            ;;
+        aarch64|arm64)
+            target="aarch64-unknown-linux-gnu"
+            checksum="e3853c5a252fca15252d07cb23a1bdd9377a8c6f3efa01531109281ae47f841c"
+            ;;
+        *)
+            echo "unsupported architecture for rustup-init: $(uname -m)"
+            exit 1
+            ;;
+    esac
+
+    tmp_dir=$(mktemp -d)
+    tmp="${tmp_dir}/rustup-init"
+    curl -fsSLo "$tmp" "https://static.rust-lang.org/rustup/archive/${version}/${target}/rustup-init"
+    echo "${checksum}  ${tmp}" | sha256sum -c -
+    chmod +x "$tmp"
+    "$tmp" -y --profile minimal --default-toolchain stable
+    export PATH="${HOME}/.cargo/bin:${PATH}"
+    ln -sf "${HOME}/.cargo/bin/cargo" /usr/local/bin/cargo
+    ln -sf "${HOME}/.cargo/bin/rustc" /usr/local/bin/rustc
+}
+
 linux_get_dependencies () {
     apt update
-    apt install -y cpanminus build-essential libncurses5-dev libreadline-dev libssl-dev perl libpcre3 libpcre3-dev libpcre2-dev xz-utils redis-tools
+    apt install -y cargo cpanminus build-essential libncurses5-dev libreadline-dev libssl-dev perl libpcre3 libpcre3-dev libpcre2-dev xz-utils redis-tools
+    install_recent_rust_toolchain
     apt remove -y curl
     apt-get install -y libyaml-dev
     wget https://github.com/mikefarah/yq/releases/download/3.4.1/yq_linux_amd64 -O /usr/bin/yq && sudo chmod +x /usr/bin/yq
 
     # install curl with http3 support
     install_curl
+
 }
 
 function start_grpc_server_example() {

conf/config.yaml.example

@@ -44,6 +44,9 @@ apisix:
   enable_server_tokens: true           # If true, show APISIX version in the `Server` response header.
   extra_lua_path: ""                   # Extend lua_package_path to load third-party code.
   extra_lua_cpath: ""                  # Extend lua_package_cpath to load third-party code.
+  request_body_json_lib: qjson         # JSON library used to decode request bodies parsed by core.request.
+                                       # Also controls AI upstream request body encoding.
+                                       # Can be cjson, simdjson, or qjson.
   # lua_module_hook: "my_project.my_hook"  # Hook module used to inject third-party code into APISIX.
 
   proxy_cache:      # Proxy Caching configuration

docs/en/latest/plugins/ai-proxy.md

@@ -42,6 +42,27 @@ The `ai-proxy` Plugin simplifies access to LLM and embedding models by transform
 
 In addition, the Plugin also supports logging LLM request information in the access log, such as token usage, model, time to the first response, and more. These log entries are also consumed by logging plugins such as `http-logger` and `kafka-logger`. These options do not affect `error.log`.
 
+## Request Body JSON Library
+
+APISIX uses `apisix.request_body_json_lib` to select the JSON library for request body parsing through `core.request.get_request_body_table`. This is a core request helper, so the setting affects every Plugin that reads JSON request bodies through this API, including `ai-proxy` and other AI Plugins. It also controls JSON encoding for AI upstream request bodies.
+
+```yaml title="conf/config.yaml"
+apisix:
+  request_body_json_lib: qjson
+```
+
+Valid values are `cjson`, `simdjson`, and `qjson`. The default is `qjson`. When `simdjson` is configured, APISIX uses `simdjson` to decode request bodies and `cjson` to encode AI upstream request bodies.
+
+The following benchmark data was measured with large OpenAI chat completion payloads and `post_arg.model` route matching, which triggers request body JSON parsing during route matching. The `qjson` result uses qjson for both request body decode and AI upstream request body encode.
+
+| Payload | `cjson` QPS | `simdjson` QPS | `qjson` QPS | `simdjson` vs `cjson` | `qjson` vs `cjson` |
+|---------|-------------|----------------|-------------|------------------------|--------------------|
+| 1 MB    | 173         | 250            | 604         | 1.45x                  | 3.41x              |
+| 5 MB    | 38          | 48-54          | 146-147     | 1.24x                  | 3.85x              |
+| 10 MB   | 17.4        | 27.4           | 77.9        | 1.58x                  | 4.48x              |
+
+Use `qjson` for the best throughput on large AI request bodies. Use `simdjson` when you only want to accelerate request body decoding while keeping `cjson` encoding semantics for AI upstream request bodies.
+
 ## Request Format
 
 | Name               | Type   | Required | Description                                         |

docs/zh/latest/plugins/ai-proxy.md

@@ -42,6 +42,27 @@ import TabItem from '@theme/TabItem';
 
 此外，该插件还支持在访问日志中记录 LLM 请求信息，如令牌使用量、模型、首次响应时间等。这些日志条目也会被 `http-logger`、`kafka-logger` 等日志插件消费。这些选项不影响 `error.log`。
 
+## 请求体 JSON 库
+
+APISIX 使用 `apisix.request_body_json_lib` 选择 `core.request.get_request_body_table` 解析请求体时使用的 JSON 库。该入口是核心请求辅助接口，因此该配置会影响所有通过此接口读取 JSON 请求体的插件，包括 `ai-proxy` 和其他 AI 插件。该配置也会控制 AI 上游请求体的 JSON 编码。
+
+```yaml title="conf/config.yaml"
+apisix:
+  request_body_json_lib: qjson
+```
+
+有效值为 `cjson`、`simdjson` 和 `qjson`，默认值为 `qjson`。当配置为 `simdjson` 时，APISIX 使用 `simdjson` 解码请求体，并使用 `cjson` 编码 AI 上游请求体。
+
+以下性能数据来自使用大 OpenAI chat completion 请求体和 `post_arg.model` 路由匹配的 benchmark，因此路由匹配阶段也会触发请求体 JSON 解析。`qjson` 结果表示请求体解码和 AI 上游请求体编码都使用 qjson。
+
+| 请求体大小 | `cjson` QPS | `simdjson` QPS | `qjson` QPS | `simdjson` 相对 `cjson` | `qjson` 相对 `cjson` |
+|------------|-------------|----------------|-------------|--------------------------|----------------------|
+| 1 MB       | 173         | 250            | 604         | 1.45x                    | 3.41x                |
+| 5 MB       | 38          | 48-54          | 146-147     | 1.24x                    | 3.85x                |
+| 10 MB      | 17.4        | 27.4           | 77.9        | 1.58x                    | 4.48x                |
+
+如果希望在大 AI 请求体场景获得最高吞吐，推荐使用 `qjson`。如果只希望加速请求体解码，同时保持 AI 上游请求体使用 `cjson` 编码语义，可以使用 `simdjson`。
+
 ## 请求格式
 
 | 名称               | 类型   | 必选项 | 描述                                         |