filter to only releases in the last year

src/main.zig

@@ -18,6 +18,9 @@ const zeit = @import("zeit");
 
 const Provider = @import("Provider.zig");
 
+// Configuration: Only include releases from the last year in the output
+const RELEASE_AGE_LIMIT_SECONDS: i64 = 365 * 24 * 60 * 60; // 1 year in seconds
+
 pub const Release = struct {
     repo_name: []const u8,
     tag_name: []const u8,
@@ -147,27 +150,38 @@ pub fn main() !u8 {
         print("Found {} new releases from {s}\n", .{ result.releases.items.len, result.provider_name });
     }
 
-    // Combine existing and new releases
+    // Combine all releases (existing and new)
     var all_releases = ArrayList(Release).init(allocator);
     defer all_releases.deinit();
 
-    // Add new releases first (they'll appear at the top of the Atom feed)
+    // Add new releases
     try all_releases.appendSlice(new_releases.items);
 
-    // Add existing releases (up to a reasonable limit to prevent Atom feed from growing indefinitely)
-    const max_total_releases = 1000;
-    const remaining_slots = if (new_releases.items.len < max_total_releases)
-        max_total_releases - new_releases.items.len
-    else
-        0;
-
-    const existing_to_add = @min(existing_releases.items.len, remaining_slots);
-    try all_releases.appendSlice(existing_releases.items[0..existing_to_add]);
+    // Add all existing releases
+    try all_releases.appendSlice(existing_releases.items);
 
     // Sort all releases by published date (most recent first)
     std.mem.sort(Release, all_releases.items, {}, compareReleasesByDate);
 
-    // Generate Atom feed
+    // Filter releases by age in-place - zero extra allocations
+    const now = std.time.timestamp();
+    const cutoff_time = now - RELEASE_AGE_LIMIT_SECONDS;
+
+    var write_index: usize = 0;
+    const original_count = all_releases.items.len;
+
+    for (all_releases.items) |release| {
+        const release_time = parseReleaseTimestamp(release.published_at) catch 0;
+        if (release_time >= cutoff_time) {
+            all_releases.items[write_index] = release;
+            write_index += 1;
+        }
+    }
+
+    // Shrink the array to only include filtered items
+    all_releases.shrinkRetainingCapacity(write_index);
+
+    // Generate Atom feed from filtered releases
     const atom_content = try atom.generateFeed(allocator, all_releases.items);
     defer allocator.free(atom_content);
 
@@ -178,7 +192,7 @@ pub fn main() !u8 {
 
     // Log to stderr for user feedback
     std.debug.print("Found {} new releases\n", .{new_releases.items.len});
-    std.debug.print("Total releases in feed: {}\n", .{all_releases.items.len});
+    std.debug.print("Total releases in feed: {} (filtered from {} total, showing last {} days)\n", .{ all_releases.items.len, original_count, @divTrunc(RELEASE_AGE_LIMIT_SECONDS, 24 * 60 * 60) });
     std.debug.print("Updated feed written to: {s}\n", .{output_file});
 
     return 0;
@@ -761,6 +775,92 @@ test {
     std.testing.refAllDecls(@import("xml_parser_tests.zig"));
 }
 
+test "Age-based release filtering" {
+    const allocator = std.testing.allocator;
+
+    const now = std.time.timestamp();
+    const one_year_ago = now - RELEASE_AGE_LIMIT_SECONDS;
+    const two_years_ago = now - (2 * RELEASE_AGE_LIMIT_SECONDS);
+
+    // Create releases with different ages
+    const recent_release = Release{
+        .repo_name = "test/recent",
+        .tag_name = "v1.0.0",
+        .published_at = try std.fmt.allocPrint(allocator, "{}", .{now - 86400}), // 1 day ago
+        .html_url = "https://github.com/test/recent/releases/tag/v1.0.0",
+        .description = "Recent release",
+        .provider = "github",
+    };
+    defer allocator.free(recent_release.published_at);
+
+    const old_release = Release{
+        .repo_name = "test/old",
+        .tag_name = "v0.1.0",
+        .published_at = try std.fmt.allocPrint(allocator, "{}", .{two_years_ago}),
+        .html_url = "https://github.com/test/old/releases/tag/v0.1.0",
+        .description = "Old release",
+        .provider = "github",
+    };
+    defer allocator.free(old_release.published_at);
+
+    const borderline_release = Release{
+        .repo_name = "test/borderline",
+        .tag_name = "v0.5.0",
+        .published_at = try std.fmt.allocPrint(allocator, "{}", .{one_year_ago + 3600}), // 1 hour within limit
+        .html_url = "https://github.com/test/borderline/releases/tag/v0.5.0",
+        .description = "Borderline release",
+        .provider = "github",
+    };
+    defer allocator.free(borderline_release.published_at);
+
+    const releases = [_]Release{ recent_release, old_release, borderline_release };
+
+    // Test filtering logic
+    var filtered = ArrayList(Release).init(allocator);
+    defer filtered.deinit();
+
+    const cutoff_time = now - RELEASE_AGE_LIMIT_SECONDS;
+
+    for (releases) |release| {
+        const release_time = parseReleaseTimestamp(release.published_at) catch 0;
+        if (release_time >= cutoff_time) {
+            try filtered.append(release);
+        }
+    }
+
+    // Should include recent and borderline, but not old
+    try std.testing.expectEqual(@as(usize, 2), filtered.items.len);
+
+    // Verify the correct releases were included
+    var found_recent = false;
+    var found_borderline = false;
+    var found_old = false;
+
+    for (filtered.items) |release| {
+        if (std.mem.eql(u8, release.repo_name, "test/recent")) {
+            found_recent = true;
+        } else if (std.mem.eql(u8, release.repo_name, "test/borderline")) {
+            found_borderline = true;
+        } else if (std.mem.eql(u8, release.repo_name, "test/old")) {
+            found_old = true;
+        }
+    }
+
+    try std.testing.expect(found_recent);
+    try std.testing.expect(found_borderline);
+    try std.testing.expect(!found_old);
+}
+
+test "RELEASE_AGE_LIMIT_SECONDS constant verification" {
+    // Verify the constant is set to 1 year in seconds
+    const expected_year_in_seconds = 365 * 24 * 60 * 60;
+    try std.testing.expectEqual(expected_year_in_seconds, RELEASE_AGE_LIMIT_SECONDS);
+
+    // Verify it's approximately 31.5 million seconds (1 year)
+    try std.testing.expect(RELEASE_AGE_LIMIT_SECONDS > 31_000_000);
+    try std.testing.expect(RELEASE_AGE_LIMIT_SECONDS < 32_000_000);
+}
+
 // Import timestamp tests
 test {
     std.testing.refAllDecls(@import("timestamp_tests.zig"));