zig fetch: handle redirects for Git packages

Closes #21976
This commit is contained in:
Ian Johnson 2024-11-18 22:59:10 -05:00 committed by Andrew Kelley
parent fbcb00fbb3
commit dceab4502a
2 changed files with 106 additions and 71 deletions

View File

@ -812,6 +812,7 @@ const Resource = union(enum) {
dir: fs.Dir,
const Git = struct {
session: git.Session,
fetch_stream: git.Session.FetchStream,
want_oid: [git.oid_length]u8,
};
@ -820,7 +821,10 @@ const Resource = union(enum) {
switch (resource.*) {
.file => |*file| file.close(),
.http_request => |*req| req.deinit(),
.git => |*git_resource| git_resource.fetch_stream.deinit(),
.git => |*git_resource| {
git_resource.fetch_stream.deinit();
git_resource.session.deinit();
},
.dir => |*dir| dir.close(),
}
resource.* = undefined;
@ -961,23 +965,13 @@ fn initResource(f: *Fetch, uri: std.Uri, server_header_buffer: []u8) RunError!Re
{
var transport_uri = uri;
transport_uri.scheme = uri.scheme["git+".len..];
var redirect_uri: []u8 = undefined;
var session: git.Session = .{ .transport = http_client, .uri = transport_uri };
session.discoverCapabilities(gpa, &redirect_uri, server_header_buffer) catch |err| switch (err) {
error.Redirected => {
defer gpa.free(redirect_uri);
return f.fail(f.location_tok, try eb.printString(
"repository moved to {s}",
.{redirect_uri},
));
},
else => |e| {
return f.fail(f.location_tok, try eb.printString(
"unable to discover remote git server capabilities: {s}",
.{@errorName(e)},
));
},
var session = git.Session.init(gpa, http_client, transport_uri, server_header_buffer) catch |err| {
return f.fail(f.location_tok, try eb.printString(
"unable to discover remote git server capabilities: {s}",
.{@errorName(err)},
));
};
errdefer session.deinit();
const want_oid = want_oid: {
const want_ref =
@ -987,7 +981,7 @@ fn initResource(f: *Fetch, uri: std.Uri, server_header_buffer: []u8) RunError!Re
const want_ref_head = try std.fmt.allocPrint(arena, "refs/heads/{s}", .{want_ref});
const want_ref_tag = try std.fmt.allocPrint(arena, "refs/tags/{s}", .{want_ref});
var ref_iterator = session.listRefs(gpa, .{
var ref_iterator = session.listRefs(.{
.ref_prefixes = &.{ want_ref, want_ref_head, want_ref_tag },
.include_peeled = true,
.server_header_buffer = server_header_buffer,
@ -1035,7 +1029,7 @@ fn initResource(f: *Fetch, uri: std.Uri, server_header_buffer: []u8) RunError!Re
_ = std.fmt.bufPrint(&want_oid_buf, "{}", .{
std.fmt.fmtSliceHexLower(&want_oid),
}) catch unreachable;
var fetch_stream = session.fetch(gpa, &.{&want_oid_buf}, server_header_buffer) catch |err| {
var fetch_stream = session.fetch(&.{&want_oid_buf}, server_header_buffer) catch |err| {
return f.fail(f.location_tok, try eb.printString(
"unable to create fetch stream: {s}",
.{@errorName(err)},
@ -1044,6 +1038,7 @@ fn initResource(f: *Fetch, uri: std.Uri, server_header_buffer: []u8) RunError!Re
errdefer fetch_stream.deinit();
return .{ .git = .{
.session = session,
.fetch_stream = fetch_stream,
.want_oid = want_oid,
} };

View File

@ -492,26 +492,31 @@ const Packet = union(enum) {
/// [protocol-v2](https://git-scm.com/docs/protocol-v2).
pub const Session = struct {
transport: *std.http.Client,
uri: std.Uri,
supports_agent: bool = false,
supports_shallow: bool = false,
location: Location,
supports_agent: bool,
supports_shallow: bool,
allocator: Allocator,
const agent = "zig/" ++ @import("builtin").zig_version_string;
const agent_capability = std.fmt.comptimePrint("agent={s}\n", .{agent});
/// Discovers server capabilities. This should be called before using any
/// other client functionality, or the client will be forced to default to
/// the bare minimum server requirements, which may be considerably less
/// efficient (e.g. no shallow fetches).
///
/// See the note on `getCapabilities` regarding `redirect_uri`.
pub fn discoverCapabilities(
session: *Session,
/// Initializes a client session and discovers the capabilities of the
/// server for optimal transport.
pub fn init(
allocator: Allocator,
redirect_uri: *[]u8,
transport: *std.http.Client,
uri: std.Uri,
http_headers_buffer: []u8,
) !void {
var capability_iterator = try session.getCapabilities(allocator, redirect_uri, http_headers_buffer);
) !Session {
var session: Session = .{
.transport = transport,
.location = try .init(allocator, uri),
.supports_agent = false,
.supports_shallow = false,
.allocator = allocator,
};
errdefer session.deinit();
var capability_iterator = try session.getCapabilities(http_headers_buffer);
defer capability_iterator.deinit();
while (try capability_iterator.next()) |capability| {
if (mem.eql(u8, capability.key, "agent")) {
@ -525,27 +530,63 @@ pub const Session = struct {
}
}
}
return session;
}
pub fn deinit(session: *Session) void {
session.location.deinit(session.allocator);
session.* = undefined;
}
/// An owned `std.Uri` representing the location of the server (base URI).
const Location = struct {
uri: std.Uri,
fn init(allocator: Allocator, uri: std.Uri) !Location {
const scheme = try allocator.dupe(u8, uri.scheme);
errdefer allocator.free(scheme);
const user = if (uri.user) |user| try std.fmt.allocPrint(allocator, "{user}", .{user}) else null;
errdefer if (user) |s| allocator.free(s);
const password = if (uri.password) |password| try std.fmt.allocPrint(allocator, "{password}", .{password}) else null;
errdefer if (password) |s| allocator.free(s);
const host = if (uri.host) |host| try std.fmt.allocPrint(allocator, "{host}", .{host}) else null;
errdefer if (host) |s| allocator.free(s);
const path = try std.fmt.allocPrint(allocator, "{path}", .{uri.path});
errdefer allocator.free(path);
// The query and fragment are not used as part of the base server URI.
return .{
.uri = .{
.scheme = scheme,
.user = if (user) |s| .{ .percent_encoded = s } else null,
.password = if (password) |s| .{ .percent_encoded = s } else null,
.host = if (host) |s| .{ .percent_encoded = s } else null,
.port = uri.port,
.path = .{ .percent_encoded = path },
},
};
}
fn deinit(loc: *Location, allocator: Allocator) void {
allocator.free(loc.uri.scheme);
if (loc.uri.user) |user| allocator.free(user.percent_encoded);
if (loc.uri.password) |password| allocator.free(password.percent_encoded);
if (loc.uri.host) |host| allocator.free(host.percent_encoded);
allocator.free(loc.uri.path.percent_encoded);
}
};
/// Returns an iterator over capabilities supported by the server.
///
/// If the server redirects the request, `error.Redirected` is returned and
/// `redirect_uri` is populated with the URI resulting from the redirects.
/// When this occurs, the value of `redirect_uri` must be freed with
/// `allocator` when the caller is done with it.
fn getCapabilities(
session: Session,
allocator: Allocator,
redirect_uri: *[]u8,
http_headers_buffer: []u8,
) !CapabilityIterator {
var info_refs_uri = session.uri;
/// The `session.location` is updated if the server returns a redirect, so
/// that subsequent session functions do not need to handle redirects.
fn getCapabilities(session: *Session, http_headers_buffer: []u8) !CapabilityIterator {
var info_refs_uri = session.location.uri;
{
const session_uri_path = try std.fmt.allocPrint(allocator, "{path}", .{session.uri.path});
defer allocator.free(session_uri_path);
info_refs_uri.path = .{ .percent_encoded = try std.fs.path.resolvePosix(allocator, &.{ "/", session_uri_path, "info/refs" }) };
const session_uri_path = try std.fmt.allocPrint(session.allocator, "{path}", .{session.location.uri.path});
defer session.allocator.free(session_uri_path);
info_refs_uri.path = .{ .percent_encoded = try std.fs.path.resolvePosix(session.allocator, &.{ "/", session_uri_path, "info/refs" }) };
}
defer allocator.free(info_refs_uri.path.percent_encoded);
defer session.allocator.free(info_refs_uri.path.percent_encoded);
info_refs_uri.query = .{ .percent_encoded = "service=git-upload-pack" };
info_refs_uri.fragment = null;
@ -565,14 +606,14 @@ pub const Session = struct {
if (request.response.status != .ok) return error.ProtocolError;
const any_redirects_occurred = request.redirect_behavior.remaining() < max_redirects;
if (any_redirects_occurred) {
const request_uri_path = try std.fmt.allocPrint(allocator, "{path}", .{request.uri.path});
defer allocator.free(request_uri_path);
const request_uri_path = try std.fmt.allocPrint(session.allocator, "{path}", .{request.uri.path});
defer session.allocator.free(request_uri_path);
if (!mem.endsWith(u8, request_uri_path, "/info/refs")) return error.UnparseableRedirect;
var new_uri = request.uri;
new_uri.path = .{ .percent_encoded = request_uri_path[0 .. request_uri_path.len - "/info/refs".len] };
new_uri.query = null;
redirect_uri.* = try std.fmt.allocPrint(allocator, "{+/}", .{new_uri});
return error.Redirected;
const new_location: Location = try .init(session.allocator, new_uri);
session.location.deinit(session.allocator);
session.location = new_location;
}
const reader = request.reader();
@ -649,28 +690,28 @@ pub const Session = struct {
};
/// Returns an iterator over refs known to the server.
pub fn listRefs(session: Session, allocator: Allocator, options: ListRefsOptions) !RefIterator {
var upload_pack_uri = session.uri;
pub fn listRefs(session: Session, options: ListRefsOptions) !RefIterator {
var upload_pack_uri = session.location.uri;
{
const session_uri_path = try std.fmt.allocPrint(allocator, "{path}", .{session.uri.path});
defer allocator.free(session_uri_path);
upload_pack_uri.path = .{ .percent_encoded = try std.fs.path.resolvePosix(allocator, &.{ "/", session_uri_path, "git-upload-pack" }) };
const session_uri_path = try std.fmt.allocPrint(session.allocator, "{path}", .{session.location.uri.path});
defer session.allocator.free(session_uri_path);
upload_pack_uri.path = .{ .percent_encoded = try std.fs.path.resolvePosix(session.allocator, &.{ "/", session_uri_path, "git-upload-pack" }) };
}
defer allocator.free(upload_pack_uri.path.percent_encoded);
defer session.allocator.free(upload_pack_uri.path.percent_encoded);
upload_pack_uri.query = null;
upload_pack_uri.fragment = null;
var body: std.ArrayListUnmanaged(u8) = .empty;
defer body.deinit(allocator);
const body_writer = body.writer(allocator);
defer body.deinit(session.allocator);
const body_writer = body.writer(session.allocator);
try Packet.write(.{ .data = "command=ls-refs\n" }, body_writer);
if (session.supports_agent) {
try Packet.write(.{ .data = agent_capability }, body_writer);
}
try Packet.write(.delimiter, body_writer);
for (options.ref_prefixes) |ref_prefix| {
const ref_prefix_packet = try std.fmt.allocPrint(allocator, "ref-prefix {s}\n", .{ref_prefix});
defer allocator.free(ref_prefix_packet);
const ref_prefix_packet = try std.fmt.allocPrint(session.allocator, "ref-prefix {s}\n", .{ref_prefix});
defer session.allocator.free(ref_prefix_packet);
try Packet.write(.{ .data = ref_prefix_packet }, body_writer);
}
if (options.include_symrefs) {
@ -753,23 +794,22 @@ pub const Session = struct {
/// performed if the server supports it.
pub fn fetch(
session: Session,
allocator: Allocator,
wants: []const []const u8,
http_headers_buffer: []u8,
) !FetchStream {
var upload_pack_uri = session.uri;
var upload_pack_uri = session.location.uri;
{
const session_uri_path = try std.fmt.allocPrint(allocator, "{path}", .{session.uri.path});
defer allocator.free(session_uri_path);
upload_pack_uri.path = .{ .percent_encoded = try std.fs.path.resolvePosix(allocator, &.{ "/", session_uri_path, "git-upload-pack" }) };
const session_uri_path = try std.fmt.allocPrint(session.allocator, "{path}", .{session.location.uri.path});
defer session.allocator.free(session_uri_path);
upload_pack_uri.path = .{ .percent_encoded = try std.fs.path.resolvePosix(session.allocator, &.{ "/", session_uri_path, "git-upload-pack" }) };
}
defer allocator.free(upload_pack_uri.path.percent_encoded);
defer session.allocator.free(upload_pack_uri.path.percent_encoded);
upload_pack_uri.query = null;
upload_pack_uri.fragment = null;
var body: std.ArrayListUnmanaged(u8) = .empty;
defer body.deinit(allocator);
const body_writer = body.writer(allocator);
defer body.deinit(session.allocator);
const body_writer = body.writer(session.allocator);
try Packet.write(.{ .data = "command=fetch\n" }, body_writer);
if (session.supports_agent) {
try Packet.write(.{ .data = agent_capability }, body_writer);