Add helper for showing memory usage of string container

Author: hannes-steffenhagen-diffblue

src/util/string_container.cpp

@@ -12,6 +12,8 @@ Author: Daniel Kroening, kroening@kroening.com
 #include "string_container.h"
 
 #include <cstring>
+#include <iostream>
+#include <numeric>
 
 string_ptrt::string_ptrt(const char *_s):s(_s), len(strlen(_s))
 {
@@ -74,3 +76,36 @@ unsigned string_containert::get(const std::string &s)
 
   return r;
 }
+
+void string_container_statisticst::dump_on_stream(std::ostream &out) const
+{
+  auto total_memory_usage = strings_memory_usage + vector_memory_usage +
+                            map_memory_usage + list_memory_usage;
+  out << "String container statistics:"
+      << "\n  string count: " << string_count
+      << "\n  string memory usage: " << strings_memory_usage.to_string()
+      << "\n  vector memory usage: " << vector_memory_usage.to_string()
+      << "\n  map memory usage:    " << map_memory_usage.to_string()
+      << "\n  list memory usage:   " << list_memory_usage.to_string()
+      << "\n  total memory usage:  " << total_memory_usage.to_string() << '\n';
+}
+
+string_container_statisticst string_containert::compute_statistics() const
+{
+  string_container_statisticst result;
+  result.string_count = string_vector.size();
+  result.vector_memory_usage = memory_sizet::from_bytes(
+    sizeof(string_vector) +
+    sizeof(string_vectort::value_type) * string_vector.capacity());
+  result.strings_memory_usage = memory_sizet::from_bytes(std::accumulate(
+    begin(string_vector),
+    end(string_vector),
+    std::size_t(0),
+    [](std::size_t sz, const std::string *s) { return sz + s->capacity(); }));
+  result.map_memory_usage = memory_sizet::from_bytes(
+    sizeof(hash_table) + hash_table.size() * sizeof(hash_tablet::value_type));
+
+  result.list_memory_usage = memory_sizet::from_bytes(
+    sizeof(string_list) + 2 * sizeof(void *) * string_list.size());
+  return result;
+}

src/util/string_container.h

@@ -16,6 +16,7 @@ Author: Daniel Kroening, kroening@kroening.com
 #include <unordered_map>
 #include <vector>
 
+#include "memory_units.h"
 #include "string_hash.h"
 
 struct string_ptrt
@@ -44,6 +45,21 @@ class string_ptr_hash
   size_t operator()(const string_ptrt s) const { return hash_string(s.s); }
 };
 
+/// Has estimated statistics about string container
+/// (estimated because this only uses public information,
+///  which disregards any internal control structures that
+///  might be in use)
+struct string_container_statisticst
+{
+  std::size_t string_count;
+  memory_sizet strings_memory_usage;
+  memory_sizet vector_memory_usage;
+  memory_sizet map_memory_usage;
+  memory_sizet list_memory_usage;
+
+  void dump_on_stream(std::ostream &out) const;
+};
+
 class string_containert
 {
 public:
@@ -73,6 +89,8 @@ class string_containert
     return *string_vector[no];
   }
 
+  string_container_statisticst compute_statistics() const;
+
 protected:
   // the 'unsigned' ought to be size_t
   typedef std::unordered_map<string_ptrt, unsigned, string_ptr_hash>