fix: use phys_footprint on macOS to match Activity Monitor

Switch from MACH_TASK_BASIC_INFO (resident_size) to TASK_VM_INFO
(phys_footprint) which matches Activity Monitor's Memory column.
Also: capacity-aware heap estimation, entry counts in memory payload,
heap_bytes tests for all stores.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

site/dashboard.html

@@ -817,13 +817,12 @@ function renderMemory(mem, stats) {
   document.getElementById('memoryRss').textContent = formatBytes(mem.process_rss_bytes);
   document.getElementById('memorySub').textContent = 'est. ' + formatBytes(mem.total_estimated_bytes);
 
-  // Entry counts from sibling stats objects (avoid duplication in memory payload)
   const entryCounts = {
-    cache: stats.cache.entries,
+    cache: mem.cache_entries,
-    blocklist: stats.blocking.domains_loaded,
+    blocklist: mem.blocklist_entries,
     query_log: mem.query_log_entries,
     srtt: mem.srtt_entries,
-    overrides: stats.overrides.active,
+    overrides: mem.overrides_entries,
   };
 
   // Sidebar panel
@@ -852,7 +851,7 @@ function renderMemory(mem, stats) {
     <div class="memory-bar">${barSegments}</div>
     ${rows}
     <div class="memory-rss">
-      <span>Process RSS</span>
+      <span>Process Footprint</span>
       <span>${formatBytes(mem.process_rss_bytes)}</span>
     </div>
   `;

src/api.rs

@@ -214,12 +214,15 @@ struct BlockingStatsResponse {
 #[derive(Serialize)]
 struct MemoryStats {
     cache_bytes: usize,
+    cache_entries: usize,
     blocklist_bytes: usize,
+    blocklist_entries: usize,
     query_log_bytes: usize,
     query_log_entries: usize,
     srtt_bytes: usize,
     srtt_entries: usize,
     overrides_bytes: usize,
+    overrides_entries: usize,
     total_estimated_bytes: usize,
     process_rss_bytes: usize,
 }
@@ -553,12 +556,15 @@ async fn stats(State(ctx): State<Arc<ServerCtx>>) -> Json<StatsResponse> {
         },
         memory: MemoryStats {
             cache_bytes,
+            cache_entries: cache_len,
             blocklist_bytes,
+            blocklist_entries: bl_stats.domains_loaded,
             query_log_bytes,
             query_log_entries,
             srtt_bytes,
             srtt_entries,
             overrides_bytes,
+            overrides_entries: override_count,
             total_estimated_bytes: total_estimated,
             process_rss_bytes: crate::stats::process_rss_bytes(),
         },

src/blocklist.rs

@@ -184,17 +184,13 @@ impl BlocklistStore {
     }
 
     pub fn heap_bytes(&self) -> usize {
-        let domains: usize = self
+        // HashSet<String> stores (hash, String) per slot + 1 control byte
-            .domains
+        let per_slot_overhead = std::mem::size_of::<u64>() + std::mem::size_of::<String>() + 1;
-            .iter()
+        let domains_table = self.domains.capacity() * per_slot_overhead;
-            .map(|d| std::mem::size_of::<String>() + d.capacity())
+        let domains_heap: usize = self.domains.iter().map(|d| d.capacity()).sum();
-            .sum();
+        let allow_table = self.allowlist.capacity() * per_slot_overhead;
-        let allow: usize = self
+        let allow_heap: usize = self.allowlist.iter().map(|d| d.capacity()).sum();
-            .allowlist
+        domains_table + domains_heap + allow_table + allow_heap
-            .iter()
-            .map(|d| std::mem::size_of::<String>() + d.capacity())
-            .sum();
-        domains + allow
     }
 
     pub fn stats(&self) -> BlocklistStats {
@@ -248,6 +244,23 @@ pub fn parse_blocklist(text: &str) -> HashSet<String> {
     domains
 }
 
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn heap_bytes_grows_with_domains() {
+        let mut store = BlocklistStore::new();
+        let empty = store.heap_bytes();
+        let domains: HashSet<String> = ["example.com", "example.org", "test.net"]
+            .iter()
+            .map(|s| s.to_string())
+            .collect();
+        store.swap_domains(domains, vec![]);
+        assert!(store.heap_bytes() > empty);
+    }
+}
+
 pub async fn download_blocklists(lists: &[String]) -> Vec<(String, String)> {
     let client = reqwest::Client::builder()
         .timeout(std::time::Duration::from_secs(30))

src/cache.rs

@@ -143,11 +143,21 @@ impl DnsCache {
     }
 
     pub fn heap_bytes(&self) -> usize {
-        let mut total = 0;
+        // Outer HashMap<String, HashMap>: (hash, String, HashMap) per slot + control byte
+        let outer_slot = std::mem::size_of::<u64>()
+            + std::mem::size_of::<String>()
+            + std::mem::size_of::<HashMap<QueryType, CacheEntry>>()
+            + 1;
+        let mut total = self.entries.capacity() * outer_slot;
         for (domain, type_map) in &self.entries {
-            total += domain.capacity() + std::mem::size_of::<String>();
+            total += domain.capacity();
+            // Inner HashMap<QueryType, CacheEntry>: (hash, QueryType, CacheEntry) per slot + control byte
+            let inner_slot = std::mem::size_of::<u64>()
+                + std::mem::size_of::<QueryType>()
+                + std::mem::size_of::<CacheEntry>()
+                + 1;
+            total += type_map.capacity() * inner_slot;
             for entry in type_map.values() {
-                total += std::mem::size_of::<CacheEntry>();
                 total += entry.packet.heap_bytes();
             }
         }
@@ -206,3 +216,23 @@ fn adjust_ttls(records: &mut [DnsRecord], new_ttl: u32) {
         record.set_ttl(new_ttl);
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::packet::DnsPacket;
+
+    #[test]
+    fn heap_bytes_grows_with_entries() {
+        let mut cache = DnsCache::new(100, 1, 3600);
+        let empty = cache.heap_bytes();
+        let mut pkt = DnsPacket::new();
+        pkt.answers.push(DnsRecord::A {
+            domain: "example.com".into(),
+            addr: "1.2.3.4".parse().unwrap(),
+            ttl: 300,
+        });
+        cache.insert("example.com", QueryType::A, &pkt);
+        assert!(cache.heap_bytes() > empty);
+    }
+}

src/override_store.rs

@@ -118,16 +118,20 @@ impl OverrideStore {
     }
 
     pub fn heap_bytes(&self) -> usize {
-        self.entries
+        // HashMap<String, OverrideEntry>: (hash, String, OverrideEntry) per slot + control byte
+        let per_slot = std::mem::size_of::<u64>()
+            + std::mem::size_of::<String>()
+            + std::mem::size_of::<OverrideEntry>()
+            + 1;
+        let table = self.entries.capacity() * per_slot;
+        let heap: usize = self
+            .entries
             .iter()
             .map(|(k, v)| {
-                k.capacity()
+                k.capacity() + v.domain.capacity() + v.target.capacity() + v.record.heap_bytes()
-                    + std::mem::size_of::<OverrideEntry>()
-                    + v.domain.capacity()
-                    + v.target.capacity()
-                    + v.record.heap_bytes()
             })
-            .sum()
+            .sum();
+        table + heap
     }
 
     pub fn active_count(&self) -> usize {
@@ -167,3 +171,16 @@ fn parse_target(domain: &str, target: &str, ttl: u32) -> Result<(QueryType, DnsR
         },
     ))
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn heap_bytes_grows_with_entries() {
+        let mut store = OverrideStore::new();
+        let empty = store.heap_bytes();
+        store.insert("example.com", "1.2.3.4", 300, None).unwrap();
+        assert!(store.heap_bytes() > empty);
+    }
+}

src/packet.rs

@@ -610,4 +610,16 @@ mod tests {
             panic!("expected DNSKEY");
         }
     }
+
+    #[test]
+    fn heap_bytes_accounts_for_records() {
+        let mut pkt = DnsPacket::new();
+        let empty = pkt.heap_bytes();
+        pkt.answers.push(DnsRecord::A {
+            domain: "example.com".into(),
+            addr: "1.2.3.4".parse().unwrap(),
+            ttl: 300,
+        });
+        assert!(pkt.heap_bytes() > empty);
+    }
 }

src/query_log.rs

@@ -92,3 +92,25 @@ pub struct QueryLogFilter {
     pub since: Option<SystemTime>,
     pub limit: Option<usize>,
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn heap_bytes_grows_with_entries() {
+        let mut log = QueryLog::new(100);
+        let empty = log.heap_bytes();
+        log.push(QueryLogEntry {
+            timestamp: SystemTime::now(),
+            src_addr: "127.0.0.1:1234".parse().unwrap(),
+            domain: "example.com".into(),
+            query_type: QueryType::A,
+            path: QueryPath::Forwarded,
+            rescode: ResultCode::NOERROR,
+            latency_us: 500,
+            dnssec: DnssecStatus::Indeterminate,
+        });
+        assert!(log.heap_bytes() > empty);
+    }
+}

src/record.rs

@@ -690,4 +690,14 @@ mod tests {
         let parsed = round_trip(&rec);
         assert_eq!(rec, parsed);
     }
+
+    #[test]
+    fn heap_bytes_reflects_string_capacity() {
+        let rec = DnsRecord::CNAME {
+            domain: "a]".repeat(100),
+            host: "b".repeat(200),
+            ttl: 60,
+        };
+        assert!(rec.heap_bytes() >= 300);
+    }
 }

src/srtt.rs

@@ -101,7 +101,12 @@ impl SrttCache {
     }
 
     pub fn heap_bytes(&self) -> usize {
-        self.entries.capacity() * (std::mem::size_of::<IpAddr>() + std::mem::size_of::<SrttEntry>())
+        // HashMap stores (hash, key, value) per slot + 1 control byte
+        let per_slot = std::mem::size_of::<u64>()
+            + std::mem::size_of::<IpAddr>()
+            + std::mem::size_of::<SrttEntry>()
+            + 1;
+        self.entries.capacity() * per_slot
     }
 
     pub fn len(&self) -> usize {
@@ -307,6 +312,16 @@ mod tests {
         assert_eq!(addrs, vec![sock(1), sock(2)]);
     }
 
+    #[test]
+    fn heap_bytes_grows_with_entries() {
+        let mut cache = SrttCache::new(true);
+        let empty = cache.heap_bytes();
+        for i in 1..=10u8 {
+            cache.record_rtt(ip(i), 100, false);
+        }
+        assert!(cache.heap_bytes() > empty);
+    }
+
     #[test]
     fn eviction_removes_oldest() {
         let mut cache = SrttCache::new(true);

src/stats.rs

@@ -24,33 +24,40 @@ fn macos_rss() -> usize {
         fn task_info(
             target_task: u32,
             flavor: u32,
-            task_info_out: *mut libc_task_basic_info,
+            task_info_out: *mut TaskVmInfo,
             task_info_count: *mut u32,
         ) -> i32;
     }
+    // Partial task_vm_info_data_t — only fields up to phys_footprint.
     #[repr(C)]
-    struct libc_task_basic_info {
+    struct TaskVmInfo {
         virtual_size: u64,
+        region_count: i32,
+        page_size: i32,
         resident_size: u64,
-        resident_size_max: u64,
+        resident_size_peak: u64,
-        user_time: [u32; 2],
+        device: u64,
-        system_time: [u32; 2],
+        device_peak: u64,
-        policy: i32,
+        internal: u64,
-        suspend_count: i32,
+        internal_peak: u64,
+        external: u64,
+        external_peak: u64,
+        reusable: u64,
+        reusable_peak: u64,
+        purgeable_volatile_pmap: u64,
+        purgeable_volatile_resident: u64,
+        purgeable_volatile_virtual: u64,
+        compressed: u64,
+        compressed_peak: u64,
+        compressed_lifetime: u64,
+        phys_footprint: u64,
     }
-    const MACH_TASK_BASIC_INFO: u32 = 20;
+    const TASK_VM_INFO: u32 = 22;
-    let mut info: libc_task_basic_info = unsafe { mem::zeroed() };
+    let mut info: TaskVmInfo = unsafe { mem::zeroed() };
-    let mut count = (mem::size_of::<libc_task_basic_info>() / mem::size_of::<u32>()) as u32;
+    let mut count = (mem::size_of::<TaskVmInfo>() / mem::size_of::<u32>()) as u32;
-    let kr = unsafe {
+    let kr = unsafe { task_info(mach_task_self(), TASK_VM_INFO, &mut info, &mut count) };
-        task_info(
-            mach_task_self(),
-            MACH_TASK_BASIC_INFO,
-            &mut info,
-            &mut count,
-        )
-    };
     if kr == 0 {
-        info.resident_size as usize
+        info.phys_footprint as usize
     } else {
         0
     }
@@ -61,7 +68,7 @@ fn linux_rss() -> usize {
     extern "C" {
         fn sysconf(name: i32) -> i64;
     }
-    const SC_PAGESIZE: i32 = 30;
+    const SC_PAGESIZE: i32 = 30; // x86_64 + aarch64; differs on mips (28), sparc (29)
     let page_size = unsafe { sysconf(SC_PAGESIZE) };
     let page_size = if page_size > 0 {
         page_size as usize