general cleanup and comments

This commit is contained in:
Emil Lerch 2023-05-30 19:10:05 -07:00
parent 4d4f19d7bc
commit e0bf317706
Signed by: lobo
GPG Key ID: A7B62D657EF764F8
2 changed files with 56 additions and 20 deletions

View File

@ -58,7 +58,7 @@ pub fn zigInit(parent_allocator: *anyopaque) callconv(.C) void {
/// Converts a StringHashMap to the structure necessary for passing through the
/// C boundary. This will be called automatically for you via the handleRequest function
/// and is also used by the main processing loop to coerce request headers
pub fn toHeaders(alloc: std.mem.Allocator, headers: std.StringHashMap([]const u8)) ![*]Header {
fn toHeaders(alloc: std.mem.Allocator, headers: std.StringHashMap([]const u8)) ![*]Header {
var header_array = try std.ArrayList(Header).initCapacity(alloc, headers.count());
var iterator = headers.iterator();
while (iterator.next()) |kv| {

View File

@ -4,16 +4,37 @@ const interface = @import("interface.zig");
const Watch = @import("Watch.zig");
const config = @import("config.zig");
const log = std.log.scoped(.main);
// logging options
pub const std_options = struct {
pub const log_level = .debug;
pub const log_scope_levels = &[_]std.log.ScopeLevel{
.{ .scope = .watch, .level = .info },
};
};
const serveFn = *const fn (*interface.Request) ?*interface.Response;
const zigInitFn = *const fn (*anyopaque) void;
const requestDeinitFn = *const fn () void;
const timeout = 250;
var watcher = Watch.init(executorChanged);
var watcher_thread: ?std.Thread = null;
// Timer used by processRequest to provide ttfb/ttlb data in output
var timer: ?std.time.Timer = null;
const FullReturn = struct {
response: []u8,
executor: *Executor,
};
// Executor structure, including functions that were found in the library
// and accounting. Also contains match data to determine if an executor
// applies
const Executor = struct {
// configuration
target_prefix: []const u8,
@ -31,23 +52,15 @@ const Executor = struct {
in_request_lock: bool = false,
};
var watcher = Watch.init(executorChanged);
var watcher_thread: ?std.Thread = null;
var timer: ?std.time.Timer = null; // timer used by processRequest
const log = std.log.scoped(.main);
pub const std_options = struct {
pub const log_level = .debug;
pub const log_scope_levels = &[_]std.log.ScopeLevel{
.{ .scope = .watch, .level = .info },
};
};
const SERVE_FN_NAME = "handle_request";
const PORT = 8069;
const PORT = 8069; // TODO: Update based on environment variable
var initial_request_buffer: usize = 1; // TODO: Update based on environment variable
var executors: []Executor = undefined;
var parsed_config: config.ParsedConfig = undefined;
/// Serves a single request. Finds executor, marshalls request data for the C
/// interface, calls the executor and marshalls data back
fn serve(allocator: *std.mem.Allocator, response: *std.http.Server.Response) !*FullReturn {
// if (some path routing thing) {
const executor = try getExecutor(response.request.target);
@ -76,7 +89,7 @@ fn serve(allocator: *std.mem.Allocator, response: *std.http.Server.Response) !*F
};
var serve_result = executor.serveFn.?(&request).?; // ok for this pointer deref to fail
log.debug("target: {s}", .{response.request.target});
log.warn("response ptr: {*}", .{serve_result.ptr}); // BUG: This works in tests, but does not when compiled (even debug mode)
log.debug("response ptr: {*}", .{serve_result.ptr}); // BUG: This works in tests, but does not when compiled (even debug mode)
var slice: []u8 = serve_result.ptr[0..serve_result.len];
log.debug("response body: {s}", .{slice});
@ -100,6 +113,8 @@ fn serve(allocator: *std.mem.Allocator, response: *std.http.Server.Response) !*F
rc.response = slice;
return rc;
}
/// Gets and executor based on request data
fn getExecutor(requested_path: []const u8) !*Executor {
var executor = blk: {
for (executors) |*exec| {
@ -139,6 +154,9 @@ fn getExecutor(requested_path: []const u8) !*Executor {
return executor;
}
/// Loads all optional symbols from the dynamic library. This has two entry
/// points, though the logic around the primary request handler is slighly
/// different in each case so we can't combine those two.
fn loadOptionalSymbols(executor: *Executor) void {
if (std.c.dlsym(executor.library.?, "request_deinit")) |s| {
executor.requestDeinitFn = @ptrCast(requestDeinitFn, s);
@ -147,6 +165,11 @@ fn loadOptionalSymbols(executor: *Executor) void {
executor.zigInitFn = @ptrCast(zigInitFn, s);
}
}
/// Executor changed. This will be called by a sepearate thread that is
/// ultimately triggered from the operating system. This will wait for open
/// requests to that libary to complete, then lock out new requests until
/// the library is reloaded.
fn executorChanged(watch: usize) void {
// NOTE: This will be called off the main thread
log.debug("executor with watch {d} changed", .{watch});
@ -181,6 +204,7 @@ fn executorChanged(watch: usize) void {
}
}
/// Wrapper to the c library to make us more ziggy
fn dlopen(path: [:0]const u8) !*anyopaque {
// We need now (and local) because we're about to call it
const lib = std.c.dlopen(path, std.c.RTLD.NOW);
@ -188,7 +212,8 @@ fn dlopen(path: [:0]const u8) !*anyopaque {
return error.CouldNotOpenDynamicLibrary;
}
// fn exitApplication(sig: i32, info: *const std.os.siginfo_t, ctx_ptr: ?*const anyopaque,) callconv(.C) noreturn {
/// Exits the application, which is wired up to SIGINT. This is the only
/// exit from the application as the main function has an infinite loop
fn exitApplication(
_: i32,
_: *const std.os.siginfo_t,
@ -198,6 +223,8 @@ fn exitApplication(
std.os.exit(0);
}
/// exitApp handles deinitialization for the application and any reporting
/// that needs to happen
fn exitApp(exitcode: u8) void {
if (exitcode == 0)
std.io.getStdOut().writer().print("termination request: stopping watch\n", .{}) catch {}
@ -210,10 +237,15 @@ fn exitApp(exitcode: u8) void {
std.os.exit(exitcode);
// joining threads will hang...we're ultimately in a signal handler.
// But everything is shut down cleanly now, so I don't think it hurts to
// just kill it all
// just kill it all (NOTE: from a practical perspective, we do not seem
// to get a clean shutdown in all cases)
// if (watcher_thread) |t|
// t.join();
}
/// reloadConfig is wired to SIGHUP and will reload all executors. In its
/// current state, this is not a safe function as no connection draining
/// has been implemented. Operates off the main thread
fn reloadConfig(
_: i32,
_: *const std.os.siginfo_t,
@ -231,6 +263,8 @@ fn reloadConfig(
@panic("Could not reload config");
};
}
/// Installs all signal handlers for shutdown and configuration reload
fn installSignalHandler() !void {
var act = std.os.Sigaction{
.handler = .{ .sigaction = exitApplication },
@ -302,7 +336,6 @@ pub fn main() !void {
try bw.flush();
}
}
var parsed_config: config.ParsedConfig = undefined;
fn loadConfig(allocator: std.mem.Allocator) ![]Executor {
log.info("loading config", .{});
// We will not watch this file - let it reload on SIGHUP
@ -318,9 +351,12 @@ fn loadConfig(allocator: std.mem.Allocator) ![]Executor {
});
}
log.info("config loaded", .{});
return al.toOwnedSlice();
return al.toOwnedSlice(); // TODO: This should return a struct with the parsed config and executors
}
/// main loop calls processRequest, which is responsible for the interface
/// with logs, connection accounting, etc. The work dealing with the request
/// itself is delegated to the serve function to work with the executor
fn processRequest(allocator: *std.mem.Allocator, server: *std.http.Server, writer: anytype) !void {
const max_header_size = 8192;
if (timer == null) timer = try std.time.Timer.start();
@ -440,7 +476,7 @@ fn testRequest(request_bytes: []const u8) !void {
var aa = arena.allocator();
var bytes_allocated: usize = 0;
// pre-warm
bytes_allocated = try preWarmArena(aa, &arena, 1);
bytes_allocated = try preWarmArena(aa, &arena, initial_request_buffer);
const server_thread = try std.Thread.spawn(
.{},
processRequest,