Number cast

doc/qbk/quickref.xml

@@ -38,6 +38,7 @@
         <bridgehead renderas="sect3">Functions</bridgehead>
         <simplelist type="vert" columns="1">
           <member><link linkend="json.ref.boost__json__make_storage">make_storage</link></member>
+          <member><link linkend="json.ref.boost__json__number_cast">number_cast</link></member>
           <member><link linkend="json.ref.boost__json__parse">parse</link></member>
           <member><link linkend="json.ref.boost__json__swap">swap</link></member>
           <member><link linkend="json.ref.boost__json__to_string">to_string</link></member>

include/boost/json.hpp

@@ -16,6 +16,7 @@
 #include <boost/json/basic_parser.hpp>
 #include <boost/json/error.hpp>
 #include <boost/json/kind.hpp>
+#include <boost/json/number_cast.hpp>
 #include <boost/json/object.hpp>
 #include <boost/json/parser.hpp>
 #include <boost/json/pool.hpp>

include/boost/json/detail/buffer.hpp

@@ -67,6 +67,7 @@ class buffer
     void
     push_back(char ch) noexcept
     {
+        BOOST_ASSERT(size_ <= N - 1);
         buf_[size_++] = ch;
     }
 
@@ -87,13 +88,15 @@ class buffer
         auto dest = buf_ + size_;
         if(cp < 0x80)
         {
+            BOOST_ASSERT(size_ <= N - 1);
             dest[0] = static_cast<char>(cp);
             size_ += 1;
             return;
         }
 
         if(cp < 0x800)
         {
+            BOOST_ASSERT(size_ <= N - 2);
             dest[0] = static_cast<char>( (cp >> 6)          | 0xc0);
             dest[1] = static_cast<char>( (cp & 0x3f)        | 0x80);
             size_ += 2;
@@ -102,6 +105,7 @@ class buffer
 
         if(cp < 0x10000)
         {
+            BOOST_ASSERT(size_ <= N - 3);
             dest[0] = static_cast<char>( (cp >> 12)         | 0xe0);
             dest[1] = static_cast<char>(((cp >> 6) & 0x3f)  | 0x80);
             dest[2] = static_cast<char>( (cp       & 0x3f)  | 0x80);
@@ -110,6 +114,7 @@ class buffer
         }
 
         {
+            BOOST_ASSERT(size_ <= N - 4);
             dest[0] = static_cast<char>( (cp >> 18)         | 0xf0);
             dest[1] = static_cast<char>(((cp >> 12) & 0x3f) | 0x80);
             dest[2] = static_cast<char>(((cp >> 6)  & 0x3f) | 0x80);

include/boost/json/detail/format.hpp

@@ -23,18 +23,18 @@ int constexpr max_number_chars =
      1 +    // '-'
      5;     // unsigned 16-bit exponent
 
-inline
+BOOST_JSON_DECL
 unsigned
 format_uint64(
     char* dest,
     std::uint64_t value) noexcept;
 
-inline
+BOOST_JSON_DECL
 unsigned
 format_int64(
     char* dest, int64_t i) noexcept;
 
-inline
+BOOST_JSON_DECL
 unsigned
 format_double(
     char* dest, double d) noexcept;
@@ -44,7 +44,7 @@ format_double(
 } // boost
 
 #ifdef BOOST_JSON_HEADER_ONLY
-#include <boost/json/detail/format.ipp>
+#include <boost/json/detail/impl/format.ipp>
 #endif
 
 #endif

include/boost/json/detail/format.ipp → include/boost/json/detail/impl/format.ipp

@@ -7,8 +7,8 @@
 // Official repository: https://github.com/vinniefalco/json
 //
 
-#ifndef BOOST_JSON_DETAIL_FORMAT_IPP
-#define BOOST_JSON_DETAIL_FORMAT_IPP
+#ifndef BOOST_JSON_DETAIL_IMPL_FORMAT_IPP
+#define BOOST_JSON_DETAIL_IMPL_FORMAT_IPP
 
 #include <boost/json/detail/ryu/ryu.hpp>
 #include <cstdint>

include/boost/json/detail/number.ipp → include/boost/json/detail/impl/number.ipp

@@ -7,8 +7,8 @@
 // Official repository: https://github.com/vinniefalco/json
 //
 
-#ifndef BOOST_JSON_DETAIL_NUMBER_IPP
-#define BOOST_JSON_DETAIL_NUMBER_IPP
+#ifndef BOOST_JSON_DETAIL_IMPL_NUMBER_IPP
+#define BOOST_JSON_DETAIL_IMPL_NUMBER_IPP
 
 #include <boost/json/detail/number.hpp>
 #include <boost/json/detail/sse2.hpp>

include/boost/json/detail/raw_stack.ipp → include/boost/json/detail/impl/raw_stack.ipp

@@ -7,8 +7,8 @@
 // Official repository: https://github.com/vinniefalco/json
 //
 
-#ifndef BOOST_JSON_DETAIL_RAW_STACK_IPP
-#define BOOST_JSON_DETAIL_RAW_STACK_IPP
+#ifndef BOOST_JSON_DETAIL_IMPL_RAW_STACK_IPP
+#define BOOST_JSON_DETAIL_IMPL_RAW_STACK_IPP
 
 #include <boost/json/detail/raw_stack.hpp>
 #include <boost/json/detail/except.hpp>
@@ -29,19 +29,23 @@ reserve(std::size_t bytes)
             stack_overflow_exception());
     if( bytes < min_capacity_)
         bytes = min_capacity_;
-    if( capacity_ >
-        max_size() - capacity_)
-    {
-        bytes = max_size();
-    }
-    else
+
+    // 2x growth factor
     {
-        // 2x growth factor
-        auto hint =
-            (capacity_ * 2) & ~1;
-        if( bytes < hint)
-            bytes = hint;
+        if( capacity_ <=
+            max_size() - capacity_)
+        {
+            auto hint =
+                (capacity_ * 2) & ~1;
+            if( bytes < hint)
+                bytes = hint;
+        }
+        else
+        {
+            bytes = max_size();
+        }
     }
+
     auto base = reinterpret_cast<
         char*>(sp_->allocate(bytes));
     if(base_)

include/boost/json/detail/number.hpp

@@ -13,6 +13,7 @@
 #include <boost/json/config.hpp>
 #include <boost/json/error.hpp>
 #include <boost/json/kind.hpp>
+#include <type_traits>
 
 namespace boost {
 namespace json {
@@ -30,6 +31,8 @@ struct number
     json::kind kind;
 };
 
+//----------------------------------------------------------
+
 class number_parser
 {
     enum class state
@@ -106,7 +109,7 @@ class number_parser
 } // boost
 
 #ifdef BOOST_JSON_HEADER_ONLY
-#include <boost/json/detail/number.ipp>
+#include <boost/json/detail/impl/number.ipp>
 #endif
 
 #endif

include/boost/json/detail/number_cast.hpp

@@ -0,0 +1,165 @@
+//
+// Copyright (c) 2019 Vinnie Falco ([email protected])
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// Official repository: https://github.com/vinniefalco/json
+//
+
+#ifndef BOOST_JSON_DETAIL_NUMBER_CAST_HPP
+#define BOOST_JSON_DETAIL_NUMBER_CAST_HPP
+
+#include <boost/json/value.hpp>
+#include <limits>
+#include <type_traits>
+
+namespace boost {
+namespace json {
+namespace detail {
+
+template<class T>
+using is_signed_integral =
+    std::integral_constant<bool,
+        std::is_signed<T>::value &&
+        ! std::is_floating_point<T>::value>;
+
+template<class T>
+using is_unsigned_integral =
+    std::integral_constant<bool,
+        std::is_unsigned<T>::value &&
+        ! std::is_same<T, bool>::value>;
+
+template<class T>
+T
+number_cast(
+    value const& jv,
+    error_code& ec,
+    typename std::enable_if<
+        is_signed_integral<T>::value
+            >::type* = 0) noexcept
+{
+    T result{};
+    if(jv.kind() == kind::int64)
+    {
+        auto const i = jv.get_int64();
+        if( i > (std::numeric_limits<T>::max)() ||
+            i < (std::numeric_limits<T>::min)())
+        {
+            ec = error::not_exact;
+        }
+        else
+        {
+            result = static_cast<T>(i);
+        }
+    }
+    else if(jv.kind() == kind::uint64)
+    {
+        auto const u = jv.get_uint64();
+        if(u > static_cast<std::uint64_t>((
+            std::numeric_limits<T>::max)()))
+        {
+            ec = error::not_exact;
+        }
+        else
+        {
+            result = static_cast<T>(u);
+        }
+    }
+    else
+    {
+        BOOST_ASSERT(jv.kind() == kind::double_);
+        auto const d = jv.get_double();
+        if( d > (std::numeric_limits<T>::max)() ||
+            d < (std::numeric_limits<T>::min)() ||
+            static_cast<T>(d) != d)
+        {
+            ec = error::not_exact;
+        }
+        else
+        {
+            result = static_cast<T>(d);
+        }
+    }
+    return result;
+}
+
+template<class T>
+T
+number_cast(
+    value const& jv,
+    error_code& ec,
+    typename std::enable_if<
+        is_unsigned_integral<T>::value
+            >::type* = 0
+    ) noexcept
+{
+    T result{};
+    if(jv.kind() == kind::int64)
+    {
+        auto const i = jv.get_int64();
+        if( i < 0 || static_cast<std::uint64_t>(i) >
+            (std::numeric_limits<T>::max)())
+        {
+            ec = error::not_exact;
+        }
+        else
+        {
+            result = static_cast<T>(i);
+        }
+    }
+    else if(jv.kind() == kind::uint64)
+    {
+        auto const u = jv.get_uint64();
+        if(u > (std::numeric_limits<T>::max)())
+        {
+            ec = error::not_exact;
+        }
+        else
+        {
+            result = static_cast<T>(u);
+        }
+    }
+    else
+    {
+        BOOST_ASSERT(jv.kind() == kind::double_);
+        auto const d = jv.get_double();
+        if( d < 0 ||
+            d > (std::numeric_limits<T>::max)() ||
+            static_cast<T>(d) != d)
+        {
+            ec = error::not_exact;
+        }
+        else
+        {
+            result = static_cast<T>(d);
+        }
+    }
+    return result;
+}
+
+template<class T>
+T
+number_cast(
+    value const& jv,
+    error_code&,
+    typename std::enable_if<
+        std::is_floating_point<T>::value
+            >::type* = 0
+    ) noexcept
+{
+    if(jv.kind() == kind::int64)
+        return static_cast<T>(jv.get_int64());
+
+    if(jv.kind() == kind::uint64)
+        return static_cast<T>(jv.get_uint64());
+
+    BOOST_ASSERT(jv.kind() == kind::double_);
+    return static_cast<T>(jv.get_double());
+}
+
+} // detail
+} // json
+} // boost
+
+#endif

include/boost/json/detail/raw_stack.hpp

@@ -153,7 +153,7 @@ align_to(raw_stack& rs) noexcept
 } // boost
 
 #ifdef BOOST_JSON_HEADER_ONLY
-#include <boost/json/detail/raw_stack.ipp>
+#include <boost/json/detail/impl/raw_stack.ipp>
 #endif
 
 #endif

include/boost/json/error.hpp

@@ -114,6 +114,9 @@ enum class error
     /// integer overflow
     integer_overflow,
 
+    /// number cast is not exact
+    not_exact,
+
     /// key not found
     key_not_found,
 

include/boost/json/impl/basic_parser.ipp

@@ -123,7 +123,7 @@ write_some(
         [this, &temp](error_code& ec)
         {
             // need 4 chars for largest utf8 code point
-            if(temp.max_size() - temp.size() >= 4)
+            if(temp.size() < temp.max_size() - 4)
                 return true;
             if(is_key_)
                 this->on_key_part(temp, ec);
@@ -754,6 +754,8 @@ loop_str1:
         unsigned long cp =
             ((u0_ - 0xd800) << 10) +
              (u_  - 0xdc00);
+        if(! maybe_flush(ec))
+            goto yield;
         temp.append_utf8(cp);
         u0_ = -1;
         st_.pop();