zzstoatzz.io
prefect server in zig
add JSON path helpers, simplify events_api.zig
utilities/json.zig:
- getPath(value, "path.to.field") - navigate by dot-separated path
- getString, getInt, getBool, getFloat, getArray, getObject helpers
- extractAt(T, alloc, value, .{"path"}) - comptime typed extraction
- comprehensive tests
events_api.zig:
- parseFilterOptions: 54 lines → 28 lines using path helpers
- filterNext: simplified token field extraction
- filter: cleaner limit parsing
inspired by zat's internal/json.zig pattern
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
+58
-102
src/api/events_api.zig
+58
-102
src/api/events_api.zig
···
50
json.sendStatus(r, "{\"detail\":\"invalid json\"}", .bad_request);
51
return;
52
};
53
-
const obj = parsed.value.object;
54
55
// parse limit (default PAGE_SIZE, max PAGE_SIZE for pagination)
56
-
var limit: usize = PAGE_SIZE;
57
-
if (obj.get("limit")) |v| {
58
-
if (v == .integer) {
59
-
const l = v.integer;
60
-
if (l > 0 and l <= PAGE_SIZE) limit = @intCast(l);
61
}
62
-
}
63
64
// parse filter object
65
-
const filter_opts = parseFilterOptions(alloc, obj);
66
67
// get total count first
68
const total = db_events.countWithFilter(alloc, filter_opts) catch 0;
···
129
return;
130
}
131
132
-
const token_obj = token_parsed.value.object;
133
134
-
// extract token fields
135
-
const total: usize = blk: {
136
-
if (token_obj.get("count")) |v| {
137
-
if (v == .integer and v.integer >= 0) break :blk @intCast(v.integer);
138
-
}
139
-
break :blk 0;
140
-
};
141
142
-
const page_size: usize = blk: {
143
-
if (token_obj.get("page_size")) |v| {
144
-
if (v == .integer and v.integer > 0) break :blk @intCast(v.integer);
145
-
}
146
-
break :blk PAGE_SIZE;
147
-
};
148
-
149
-
const offset: usize = blk: {
150
-
if (token_obj.get("offset")) |v| {
151
-
if (v == .integer and v.integer >= 0) break :blk @intCast(v.integer);
152
-
}
153
-
break :blk 0;
154
-
};
155
156
-
// parse filter from token - extract fields directly from token_obj.filter
157
var filter_opts = db_events.FilterOptions{};
158
-
if (token_obj.get("filter")) |filter_val| {
159
-
if (filter_val == .object) {
160
-
const fobj = filter_val.object;
161
-
if (fobj.get("occurred_since")) |v| {
162
-
if (v == .string) filter_opts.occurred_since = v.string;
163
-
}
164
-
if (fobj.get("occurred_until")) |v| {
165
-
if (v == .string) filter_opts.occurred_until = v.string;
166
-
}
167
-
if (fobj.get("event_prefixes")) |v| {
168
-
filter_opts.event_prefixes = db_events.parseJsonStringArray(alloc, v);
169
-
}
170
-
if (fobj.get("event_names")) |v| {
171
-
filter_opts.event_names = db_events.parseJsonStringArray(alloc, v);
172
-
}
173
-
if (fobj.get("resource_ids")) |v| {
174
-
filter_opts.resource_ids = db_events.parseJsonStringArray(alloc, v);
175
-
}
176
-
if (fobj.get("resource_id_prefixes")) |v| {
177
-
filter_opts.resource_id_prefixes = db_events.parseJsonStringArray(alloc, v);
178
-
}
179
-
if (fobj.get("order_asc")) |v| {
180
-
if (v == .bool) filter_opts.order_asc = v.bool;
181
-
}
182
-
}
183
}
184
185
// query this page
···
196
sendEventPage(r, alloc, events, total, next_page);
197
}
198
199
-
fn parseFilterOptions(alloc: std.mem.Allocator, obj: std.json.ObjectMap) db_events.FilterOptions {
200
-
var filter_opts = db_events.FilterOptions{};
201
-
202
-
if (obj.get("filter")) |filter_val| {
203
-
if (filter_val == .object) {
204
-
const fobj = filter_val.object;
205
206
-
// occurred filter: { "since": "...", "until": "..." }
207
-
if (fobj.get("occurred")) |occ| {
208
-
if (occ == .object) {
209
-
if (occ.object.get("since")) |v| {
210
-
if (v == .string) filter_opts.occurred_since = v.string;
211
-
}
212
-
if (occ.object.get("until")) |v| {
213
-
if (v == .string) filter_opts.occurred_until = v.string;
214
-
}
215
-
}
216
-
}
217
218
-
// event filter: { "prefix": ["..."], "name": ["..."] }
219
-
if (fobj.get("event")) |ev| {
220
-
if (ev == .object) {
221
-
if (ev.object.get("prefix")) |v| {
222
-
filter_opts.event_prefixes = db_events.parseJsonStringArray(alloc, v);
223
-
}
224
-
if (ev.object.get("name")) |v| {
225
-
filter_opts.event_names = db_events.parseJsonStringArray(alloc, v);
226
-
}
227
-
}
228
-
}
229
230
-
// resource filter: { "id": ["..."], "id_prefix": ["..."] }
231
-
if (fobj.get("resource")) |res| {
232
-
if (res == .object) {
233
-
if (res.object.get("id")) |v| {
234
-
filter_opts.resource_ids = db_events.parseJsonStringArray(alloc, v);
235
-
}
236
-
if (res.object.get("id_prefix")) |v| {
237
-
filter_opts.resource_id_prefixes = db_events.parseJsonStringArray(alloc, v);
238
-
}
239
-
}
240
-
}
241
242
-
// order: "ASC" or "DESC"
243
-
if (fobj.get("order")) |v| {
244
-
if (v == .string) {
245
-
if (mem.eql(u8, v.string, "ASC")) filter_opts.order_asc = true;
246
-
}
247
-
}
248
-
}
249
}
250
251
-
return filter_opts;
252
}
253
254
fn generateNextPageUrl(
···
50
json.sendStatus(r, "{\"detail\":\"invalid json\"}", .bad_request);
51
return;
52
};
53
54
// parse limit (default PAGE_SIZE, max PAGE_SIZE for pagination)
55
+
const limit: usize = blk: {
56
+
if (json.getInt(parsed.value, "limit")) |l| {
57
+
if (l > 0 and l <= PAGE_SIZE) break :blk @intCast(l);
58
}
59
+
break :blk PAGE_SIZE;
60
+
};
61
62
// parse filter object
63
+
const filter_opts = parseFilterOptions(alloc, parsed.value);
64
65
// get total count first
66
const total = db_events.countWithFilter(alloc, filter_opts) catch 0;
···
127
return;
128
}
129
130
+
// extract token fields using path helpers
131
+
const total: usize = if (json.getInt(token_parsed.value, "count")) |c|
132
+
if (c >= 0) @intCast(c) else 0
133
+
else
134
+
0;
135
136
+
const page_size: usize = if (json.getInt(token_parsed.value, "page_size")) |ps|
137
+
if (ps > 0) @intCast(ps) else PAGE_SIZE
138
+
else
139
+
PAGE_SIZE;
140
141
+
const offset: usize = if (json.getInt(token_parsed.value, "offset")) |o|
142
+
if (o >= 0) @intCast(o) else 0
143
+
else
144
+
0;
145
146
+
// parse filter from token
147
var filter_opts = db_events.FilterOptions{};
148
+
filter_opts.occurred_since = json.getString(token_parsed.value, "filter.occurred_since");
149
+
filter_opts.occurred_until = json.getString(token_parsed.value, "filter.occurred_until");
150
+
filter_opts.order_asc = json.getBool(token_parsed.value, "filter.order_asc") orelse false;
151
+
152
+
if (json.getPath(token_parsed.value, "filter.event_prefixes")) |v| {
153
+
filter_opts.event_prefixes = db_events.parseJsonStringArray(alloc, v);
154
+
}
155
+
if (json.getPath(token_parsed.value, "filter.event_names")) |v| {
156
+
filter_opts.event_names = db_events.parseJsonStringArray(alloc, v);
157
+
}
158
+
if (json.getPath(token_parsed.value, "filter.resource_ids")) |v| {
159
+
filter_opts.resource_ids = db_events.parseJsonStringArray(alloc, v);
160
+
}
161
+
if (json.getPath(token_parsed.value, "filter.resource_id_prefixes")) |v| {
162
+
filter_opts.resource_id_prefixes = db_events.parseJsonStringArray(alloc, v);
163
}
164
165
// query this page
···
176
sendEventPage(r, alloc, events, total, next_page);
177
}
178
179
+
fn parseFilterOptions(alloc: std.mem.Allocator, value: std.json.Value) db_events.FilterOptions {
180
+
var opts = db_events.FilterOptions{};
181
182
+
// occurred filter
183
+
opts.occurred_since = json.getString(value, "filter.occurred.since");
184
+
opts.occurred_until = json.getString(value, "filter.occurred.until");
185
186
+
// event filter
187
+
if (json.getPath(value, "filter.event.prefix")) |v| {
188
+
opts.event_prefixes = db_events.parseJsonStringArray(alloc, v);
189
+
}
190
+
if (json.getPath(value, "filter.event.name")) |v| {
191
+
opts.event_names = db_events.parseJsonStringArray(alloc, v);
192
+
}
193
194
+
// resource filter
195
+
if (json.getPath(value, "filter.resource.id")) |v| {
196
+
opts.resource_ids = db_events.parseJsonStringArray(alloc, v);
197
+
}
198
+
if (json.getPath(value, "filter.resource.id_prefix")) |v| {
199
+
opts.resource_id_prefixes = db_events.parseJsonStringArray(alloc, v);
200
+
}
201
202
+
// order
203
+
if (json.getString(value, "filter.order")) |order| {
204
+
opts.order_asc = mem.eql(u8, order, "ASC");
205
}
206
207
+
return opts;
208
}
209
210
fn generateNextPageUrl(
+172
src/utilities/json.zig
+172
src/utilities/json.zig
···
15
r.setStatus(status);
16
send(r, body);
17
}
18
+
19
+
// ============================================================================
20
+
// JSON path navigation helpers
21
+
// ============================================================================
22
+
23
+
/// navigate a json value by dot-separated path
24
+
/// returns null if any segment is missing or wrong type
25
+
pub fn getPath(value: std.json.Value, path: []const u8) ?std.json.Value {
26
+
var current = value;
27
+
var it = std.mem.splitScalar(u8, path, '.');
28
+
29
+
while (it.next()) |segment| {
30
+
switch (current) {
31
+
.object => |obj| {
32
+
current = obj.get(segment) orelse return null;
33
+
},
34
+
.array => |arr| {
35
+
const idx = std.fmt.parseInt(usize, segment, 10) catch return null;
36
+
if (idx >= arr.items.len) return null;
37
+
current = arr.items[idx];
38
+
},
39
+
else => return null,
40
+
}
41
+
}
42
+
return current;
43
+
}
44
+
45
+
/// get a string at path
46
+
pub fn getString(value: std.json.Value, path: []const u8) ?[]const u8 {
47
+
const v = getPath(value, path) orelse return null;
48
+
return switch (v) {
49
+
.string => |s| s,
50
+
else => null,
51
+
};
52
+
}
53
+
54
+
/// get an integer at path
55
+
pub fn getInt(value: std.json.Value, path: []const u8) ?i64 {
56
+
const v = getPath(value, path) orelse return null;
57
+
return switch (v) {
58
+
.integer => |i| i,
59
+
else => null,
60
+
};
61
+
}
62
+
63
+
/// get a float at path
64
+
pub fn getFloat(value: std.json.Value, path: []const u8) ?f64 {
65
+
const v = getPath(value, path) orelse return null;
66
+
return switch (v) {
67
+
.float => |f| f,
68
+
.integer => |i| @floatFromInt(i),
69
+
else => null,
70
+
};
71
+
}
72
+
73
+
/// get a bool at path
74
+
pub fn getBool(value: std.json.Value, path: []const u8) ?bool {
75
+
const v = getPath(value, path) orelse return null;
76
+
return switch (v) {
77
+
.bool => |b| b,
78
+
else => null,
79
+
};
80
+
}
81
+
82
+
/// get an array at path
83
+
pub fn getArray(value: std.json.Value, path: []const u8) ?[]std.json.Value {
84
+
const v = getPath(value, path) orelse return null;
85
+
return switch (v) {
86
+
.array => |a| a.items,
87
+
else => null,
88
+
};
89
+
}
90
+
91
+
/// get an object at path
92
+
pub fn getObject(value: std.json.Value, path: []const u8) ?std.json.ObjectMap {
93
+
const v = getPath(value, path) orelse return null;
94
+
return switch (v) {
95
+
.object => |o| o,
96
+
else => null,
97
+
};
98
+
}
99
+
100
+
// ============================================================================
101
+
// comptime path extraction
102
+
// ============================================================================
103
+
104
+
/// extract a typed struct from a nested path
105
+
/// uses comptime tuple for path segments - no runtime string parsing
106
+
/// leverages std.json.parseFromValueLeaky for type-safe extraction
107
+
pub fn extractAt(
108
+
comptime T: type,
109
+
allocator: std.mem.Allocator,
110
+
value: std.json.Value,
111
+
comptime path: anytype,
112
+
) std.json.ParseFromValueError!T {
113
+
var current = value;
114
+
inline for (path) |segment| {
115
+
current = switch (current) {
116
+
.object => |obj| obj.get(segment) orelse return error.MissingField,
117
+
else => return error.UnexpectedToken,
118
+
};
119
+
}
120
+
return std.json.parseFromValueLeaky(T, allocator, current, .{ .ignore_unknown_fields = true });
121
+
}
122
+
123
+
/// extract a typed value, returning null if path doesn't exist
124
+
pub fn extractAtOptional(
125
+
comptime T: type,
126
+
allocator: std.mem.Allocator,
127
+
value: std.json.Value,
128
+
comptime path: anytype,
129
+
) ?T {
130
+
return extractAt(T, allocator, value, path) catch null;
131
+
}
132
+
133
+
// ============================================================================
134
+
// tests
135
+
// ============================================================================
136
+
137
+
test "getPath simple" {
138
+
const json_str = "{\"name\": \"alice\", \"age\": 30}";
139
+
const parsed = try std.json.parseFromSlice(std.json.Value, std.testing.allocator, json_str, .{});
140
+
defer parsed.deinit();
141
+
try std.testing.expectEqualStrings("alice", getString(parsed.value, "name").?);
142
+
try std.testing.expectEqual(@as(i64, 30), getInt(parsed.value, "age").?);
143
+
}
144
+
145
+
test "getPath nested" {
146
+
const json_str = "{\"embed\": {\"external\": {\"uri\": \"https://example.com\"}}}";
147
+
const parsed = try std.json.parseFromSlice(std.json.Value, std.testing.allocator, json_str, .{});
148
+
defer parsed.deinit();
149
+
try std.testing.expectEqualStrings("https://example.com", getString(parsed.value, "embed.external.uri").?);
150
+
}
151
+
152
+
test "getPath array index" {
153
+
const json_str = "{\"items\": [\"a\", \"b\", \"c\"]}";
154
+
const parsed = try std.json.parseFromSlice(std.json.Value, std.testing.allocator, json_str, .{});
155
+
defer parsed.deinit();
156
+
try std.testing.expectEqualStrings("b", getString(parsed.value, "items.1").?);
157
+
}
158
+
159
+
test "getPath missing returns null" {
160
+
const json_str = "{\"name\": \"alice\"}";
161
+
const parsed = try std.json.parseFromSlice(std.json.Value, std.testing.allocator, json_str, .{});
162
+
defer parsed.deinit();
163
+
try std.testing.expect(getString(parsed.value, "missing") == null);
164
+
try std.testing.expect(getString(parsed.value, "name.nested") == null);
165
+
}
166
+
167
+
test "extractAt struct" {
168
+
const json_str = "{\"embed\": {\"external\": {\"uri\": \"https://tangled.sh\", \"title\": \"Tangled\"}}}";
169
+
var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
170
+
defer arena.deinit();
171
+
const parsed = try std.json.parseFromSlice(std.json.Value, arena.allocator(), json_str, .{});
172
+
const External = struct { uri: []const u8, title: []const u8 };
173
+
const ext = try extractAt(External, arena.allocator(), parsed.value, .{ "embed", "external" });
174
+
try std.testing.expectEqualStrings("https://tangled.sh", ext.uri);
175
+
try std.testing.expectEqualStrings("Tangled", ext.title);
176
+
}
177
+
178
+
test "extractAtOptional returns null on missing path" {
179
+
const json_str = "{\"exists\": {\"value\": 1}}";
180
+
var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
181
+
defer arena.deinit();
182
+
const parsed = try std.json.parseFromSlice(std.json.Value, arena.allocator(), json_str, .{});
183
+
const Thing = struct { value: i64 };
184
+
const exists = extractAtOptional(Thing, arena.allocator(), parsed.value, .{"exists"});
185
+
try std.testing.expect(exists != null);
186
+
try std.testing.expectEqual(@as(i64, 1), exists.?.value);
187
+
const missing = extractAtOptional(Thing, arena.allocator(), parsed.value, .{"missing"});
188
+
try std.testing.expect(missing == null);
189
+
}