fdsdump: add comparison method to View

Author: sedmicha

src/tools/fdsdump/src/aggregator/view.cpp

@@ -135,5 +135,24 @@ View::ordered_before(uint8_t *key1, uint8_t *key2) const
     return false;
 }
 
+CmpResult
+View::compare(const uint8_t *rec1, const uint8_t *rec2) const
+{
+    assert(!m_order_fields.empty());
+    for (const auto &item : m_order_fields) {
+        const Value &value1 = access_field(*item.field, rec1);
+        const Value &value2 = access_field(*item.field, rec2);
+        CmpResult res = item.field->compare(value1, value2);
+        if (res != CmpResult::Eq) {
+            if (item.dir == OrderDirection::Ascending) {
+                return res;
+            } else {
+                return res == CmpResult::Lt ? CmpResult::Gt : CmpResult::Lt;
+            }
+        }
+    }
+    return CmpResult::Eq;
+}
+
 } // aggregator
 } // fdsdump

src/tools/fdsdump/src/aggregator/view.hpp

@@ -9,9 +9,14 @@
 
 #pragma once
 
+#define XXH_INLINE_ALL
+
+#include <3rd_party/xxhash/xxhash.h>
 #include <aggregator/field.hpp>
+#include <common/common.hpp>
 
 #include <cstddef>
+#include <functional>
 #include <memory>
 #include <vector>
 
@@ -28,6 +33,10 @@ class View {
     /**
      * @brief The ordering/sorting direction
      */
+    using KeyHashFnType = std::function<uint64_t(const uint8_t *)>;
+    using KeyEqualsFnType = std::function<bool(const uint8_t *, const uint8_t *)>;
+    using RecOrdFnType = std::function<bool(const uint8_t *, const uint8_t *)>;
+
     enum class OrderDirection {
         Ascending,
         Descending
@@ -399,6 +408,45 @@ class View {
      */
     bool is_fixed_size() const { return m_is_fixed_size; }
 
+    uint64_t key_hash(const uint8_t *key) const
+    {
+        return XXH3_64bits(key, key_size(key));
+    }
+
+    bool key_equals(const uint8_t *key1, const uint8_t *key2) const
+    {
+        std::size_t key1_size = key_size(key1);
+        std::size_t key2_size = key_size(key2);
+        return key1_size == key2_size && std::memcmp(key1, key2, key1_size) == 0;
+    }
+
+    KeyHashFnType key_hasher() const
+    {
+        return [this](const uint8_t *key) { return key_hash(key); };
+    }
+
+    KeyEqualsFnType key_equaler() const
+    {
+        return [this](const uint8_t *key1, const uint8_t *key2) { return key_equals(key1, key2); };
+    }
+
+    RecOrdFnType rec_orderer() const
+    {
+        return [this](const uint8_t *rec1, const uint8_t *rec2) {
+            return compare(rec1, rec2) == CmpResult::Lt;
+        };
+    }
+
+    RecOrdFnType rec_reverse_orderer() const
+    {
+        return [this](const uint8_t *rec1, const uint8_t *rec2) {
+            return compare(rec1, rec2) == CmpResult::Gt;
+        };
+    }
+
+    CmpResult
+    compare(const uint8_t *rec1, const uint8_t *rec2) const;
+
 private:
     View() = default;