From 26e36b3a9d7b49d46ecfa69b447482251acba8ac Mon Sep 17 00:00:00 2001
From: Karen Arutyunov <karen@codesynthesis.com>
Date: Wed, 24 Jan 2024 16:53:38 +0300
Subject: Turn libodb repository into package for muti-package repository

---
 libodb/odb/result.hxx | 247 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 247 insertions(+)
 create mode 100644 libodb/odb/result.hxx

(limited to 'libodb/odb/result.hxx')

diff --git a/libodb/odb/result.hxx b/libodb/odb/result.hxx
new file mode 100644
index 0000000..87a6869
--- /dev/null
+++ b/libodb/odb/result.hxx
@@ -0,0 +1,247 @@
+// file      : odb/result.hxx
+// license   : GNU GPL v2; see accompanying LICENSE file
+
+#ifndef ODB_RESULT_HXX
+#define ODB_RESULT_HXX
+
+#include <odb/pre.hxx>
+
+#include <cstddef>  // std::ptrdiff_t, std::size_t
+
+#include <odb/forward.hxx> // odb::core
+#include <odb/traits.hxx>
+
+#include <odb/details/export.hxx>
+#include <odb/details/shared-ptr.hxx>
+
+namespace odb
+{
+  class LIBODB_EXPORT result_impl: public details::shared_base
+  {
+  public:
+    virtual
+    ~result_impl ();
+
+    virtual void
+    invalidate () = 0;
+
+  protected:
+    result_impl (connection&);
+
+  protected:
+    database& db_;
+    connection& conn_;
+
+    // Doubly-linked list of results.
+    //
+    // prev_ ==    0 means we are the first element.
+    // next_ ==    0 means we are the last element.
+    // next_ == this means we are not on the list.
+    //
+  protected:
+    friend class connection;
+
+    void
+    list_remove ();
+
+    result_impl* prev_;
+    result_impl* next_;
+  };
+
+  template <typename T, class_kind kind>
+  class result_base;
+
+  template <typename T, class_kind kind = class_traits<T>::kind>
+  class result_iterator;
+
+  // Input iterator requirements.
+  //
+  template <typename T, class_kind kind>
+  inline bool
+  operator== (result_iterator<T, kind> i, result_iterator<T, kind> j)
+  {
+    return i.equal (j);
+  }
+
+  template <typename T, class_kind kind>
+  inline bool
+  operator!= (result_iterator<T, kind> i, result_iterator<T, kind> j)
+  {
+    return !i.equal (j);
+  }
+
+  template <typename T>
+  class result: result_base<T, class_traits<T>::kind>
+  {
+  public:
+    static const class_kind kind = class_traits<T>::kind;
+
+    typedef result_base<T, kind> base;
+
+    typedef typename base::value_type value_type;
+    typedef value_type*               pointer;
+    typedef const value_type*         const_pointer;
+    typedef value_type&               reference;
+    typedef const value_type&         const_reference;
+
+    typedef result_iterator<T, kind>  iterator;
+
+    typedef std::size_t               size_type;
+    typedef std::ptrdiff_t            difference_type;
+
+    typedef typename base::result_impl_type result_impl_type;
+
+  public:
+    result ()
+    {
+    }
+
+    explicit
+    result (details::shared_ptr<result_impl_type> impl)
+        : impl_ (impl)
+    {
+    }
+
+    // Copying or assignment of a result instance leads to one instance
+    // being an alias for another. Think of copying a result as copying
+    // a file handle -- the file you access through either of them is
+    // still the same.
+    //
+  public:
+    result (const result& r)
+        : impl_ (r.impl_)
+    {
+    }
+
+    result&
+    operator= (const result& r)
+    {
+      if (impl_ != r.impl_)
+        impl_ = r.impl_;
+
+      return *this;
+    }
+
+    // Conversion from result<T> to result<const T>.
+    //
+    template <typename UT>
+    result (const result<UT>& r)
+        //
+        // If you get a compiler error pointing to the line below saying
+        // that the impl_ member is inaccessible, then you are most likely
+        // trying to perform an illegal result conversion, for example,
+        // from result<const obj> to result<obj>.
+        //
+        : impl_ (r.impl_)
+    {
+    }
+
+    template <typename UT>
+    result&
+    operator= (const result<UT>& r)
+    {
+      // If you get a compiler error pointing to the line below saying
+      // that the impl_ member is inaccessible, then you are most likely
+      // trying to perform an illegal result conversion, for example,
+      // from result<const obj> to result<obj>.
+      //
+      if (impl_ != r.impl_)
+        impl_ = r.impl_;
+
+      return *this;
+    }
+
+    void
+    swap (result& r)
+    {
+      // @@ add swap() to shared_ptr.
+      //
+      details::shared_ptr<result_impl_type> p (impl_);
+      impl_ = r.impl_;
+      r.impl_ = p;
+    }
+
+  public:
+    iterator
+    begin ()
+    {
+      if (impl_)
+        impl_->begin ();
+
+      return iterator (impl_.get ());
+    }
+
+    iterator
+    end ()
+    {
+      return iterator ();
+    }
+
+    // Cache the result instead of fetching the data from the database
+    // one row at a time. This is necessary if you plan on performing
+    // database operations while iterating over the result.
+    //
+  public:
+    void
+    cache ()
+    {
+      if (impl_)
+        impl_->cache ();
+    }
+
+  public:
+    bool
+    empty () const
+    {
+      if (impl_ == 0)
+        return true;
+
+      impl_->begin ();
+      return impl_->end ();
+    }
+
+    // Size is only known in cached results.
+    //
+    size_type
+    size () const
+    {
+      return impl_ ? impl_->size () : 0;
+    }
+
+    // query_one() and query_value() implementation details.
+    //
+  public:
+    typedef typename iterator::pointer_type pointer_type;
+
+    pointer_type
+    one ();
+
+    bool
+    one (T&);
+
+    // We cannot return by value here since result can be instantiated
+    // for an abstract type (polymorphic abstract base) and it seems
+    // the signature must be valid to the point being able to call the
+    // necessary constructors.
+    //
+    void
+    value (T&);
+
+  private:
+    friend class result<const T>;
+
+    details::shared_ptr<result_impl_type> impl_;
+  };
+
+  namespace common
+  {
+    using odb::result;
+    using odb::result_iterator;
+  }
+}
+
+#include <odb/result.txx>
+
+#include <odb/post.hxx>
+
+#endif // ODB_RESULT_HXX
-- 
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