libmeminfo: Add support for counting swap pages

Adds procmeminfo API to get the vector of swap_offsets
if SWAP is enabled on the device.

Bug: 114325007
Bug: 111694435
Test: libmeminfo_test 1
Change-Id: If0b52d042749a5bcb2c87aa2cb1595190d4769b1
Signed-off-by: Sandeep Patil <sspatil@google.com>

3 files changed, 37 insertions, 16 deletions

diff --git a/include/meminfo/meminfo.h b/include/meminfo/meminfo.h
index c328648..809054b 100644
--- a/include/meminfo/meminfo.h
+++ b/include/meminfo/meminfo.h
@@ -31,6 +31,8 @@ struct MemUsage {
     uint64_t pss;
     uint64_t uss;
 
+    uint64_t swap;
+
     uint64_t private_clean;
     uint64_t private_dirty;
     uint64_t shared_clean;
@@ -41,6 +43,7 @@ struct MemUsage {
           rss(0),
           pss(0),
           uss(0),
+          swap(0),
           private_clean(0),
           private_dirty(0),
           shared_clean(0),
@@ -49,7 +52,7 @@ struct MemUsage {
     ~MemUsage() = default;
 
     void clear() {
-        vss = rss = pss = uss = 0;
+        vss = rss = pss = uss = swap = 0;
         private_clean = private_dirty = shared_clean = shared_dirty = 0;
     }
 };
diff --git a/include/meminfo/procmeminfo.h b/include/meminfo/procmeminfo.h
index b37c56b..dd59912 100644
--- a/include/meminfo/procmeminfo.h
+++ b/include/meminfo/procmeminfo.h
@@ -34,6 +34,7 @@ class ProcMemInfo final {
     const std::vector<Vma>& Maps();
     const MemUsage& Usage();
     const MemUsage& Wss();
+    const std::vector<uint16_t>& SwapOffsets() const;
 
     bool WssReset();
     ~ProcMemInfo() = default;
@@ -49,6 +50,7 @@ class ProcMemInfo final {
 
     MemUsage usage_;
     MemUsage wss_;
+    std::vector<uint16_t> swap_offsets_;
 };
 
 }  // namespace meminfo
diff --git a/include/meminfo/sysmeminfo.h b/include/meminfo/sysmeminfo.h
index f5e05bd..87e1464 100644
--- a/include/meminfo/sysmeminfo.h
+++ b/include/meminfo/sysmeminfo.h
@@ -28,6 +28,22 @@ namespace meminfo {
 class SysMemInfo final {
     // System or Global memory accounting
   public:
+    static constexpr const char* kMemTotal = "MemTotal:";
+    static constexpr const char* kMemFree = "MemFree:";
+    static constexpr const char* kMemBuffers = "Buffers:";
+    static constexpr const char* kMemCached = "Cached:";
+    static constexpr const char* kMemShmem = "Shmem:";
+    static constexpr const char* kMemSlab = "Slab:";
+    static constexpr const char* kMemSReclaim = "SReclaimable:";
+    static constexpr const char* kMemSUnreclaim = "SUnreclaim:";
+    static constexpr const char* kMemSwapTotal = "SwapTotal:";
+    static constexpr const char* kMemSwapFree = "SwapFree:";
+    static constexpr const char* kMemZram = "Zram:";
+    static constexpr const char* kMemMapped = "Mapped:";
+    static constexpr const char* kMemVmallocUsed = "VmallocUsed:";
+    static constexpr const char* kMemPageTables = "PageTables:";
+    static constexpr const char* kMemKernelStack = "KernelStack:";
+
     static const std::vector<std::string> kDefaultSysMemInfoTags;
 
     SysMemInfo() = default;
@@ -38,21 +54,21 @@ class SysMemInfo final {
                      const std::string& path = "/proc/meminfo");
 
     // getters
-    uint64_t mem_total_kb() { return mem_in_kb_["MemTotal:"]; }
-    uint64_t mem_free_kb() { return mem_in_kb_["MemFree:"]; }
-    uint64_t mem_buffers_kb() { return mem_in_kb_["Buffers:"]; }
-    uint64_t mem_cached_kb() { return mem_in_kb_["Cached:"]; }
-    uint64_t mem_shmem_kb() { return mem_in_kb_["Shmem:"]; }
-    uint64_t mem_slab_kb() { return mem_in_kb_["Slab:"]; }
-    uint64_t mem_slab_reclailmable_kb() { return mem_in_kb_["SReclaimable:"]; }
-    uint64_t mem_slab_unreclaimable_kb() { return mem_in_kb_["SUnreclaim:"]; }
-    uint64_t mem_swap_kb() { return mem_in_kb_["SwapTotal:"]; }
-    uint64_t mem_free_swap_kb() { return mem_in_kb_["SwapFree:"]; }
-    uint64_t mem_zram_kb() { return mem_in_kb_["Zram:"]; }
-    uint64_t mem_mapped_kb() { return mem_in_kb_["Mapped:"]; }
-    uint64_t mem_vmalloc_used_kb() { return mem_in_kb_["VmallocUsed:"]; }
-    uint64_t mem_page_tables_kb() { return mem_in_kb_["PageTables:"]; }
-    uint64_t mem_kernel_stack_kb() { return mem_in_kb_["KernelStack:"]; }
+    uint64_t mem_total_kb() { return mem_in_kb_[kMemTotal]; }
+    uint64_t mem_free_kb() { return mem_in_kb_[kMemFree]; }
+    uint64_t mem_buffers_kb() { return mem_in_kb_[kMemBuffers]; }
+    uint64_t mem_cached_kb() { return mem_in_kb_[kMemCached]; }
+    uint64_t mem_shmem_kb() { return mem_in_kb_[kMemShmem]; }
+    uint64_t mem_slab_kb() { return mem_in_kb_[kMemSlab]; }
+    uint64_t mem_slab_reclailmable_kb() { return mem_in_kb_[kMemSReclaim]; }
+    uint64_t mem_slab_unreclaimable_kb() { return mem_in_kb_[kMemSUnreclaim]; }
+    uint64_t mem_swap_kb() { return mem_in_kb_[kMemSwapTotal]; }
+    uint64_t mem_swap_free_kb() { return mem_in_kb_[kMemSwapFree]; }
+    uint64_t mem_zram_kb() { return mem_in_kb_[kMemZram]; }
+    uint64_t mem_mapped_kb() { return mem_in_kb_[kMemMapped]; }
+    uint64_t mem_vmalloc_used_kb() { return mem_in_kb_[kMemVmallocUsed]; }
+    uint64_t mem_page_tables_kb() { return mem_in_kb_[kMemPageTables]; }
+    uint64_t mem_kernel_stack_kb() { return mem_in_kb_[kMemPageTables]; }
 
   private:
     std::map<std::string, uint64_t> mem_in_kb_;