Squashed 'src/mio/' changes from c7c7163a..88e0263b

88e0263b Fix memory mapped data offset
514837b2 Update test.cpp
18fbf199 Fix minor errors in internal docs
cafa3136 Merge pull request #40 from patrick--/single_header
3c655b70 Added single header file information to the README
647e9779 Initial single header support using amalgamate
3c658bf6 Merge pull request #38 from amallia/patch-1
d25c02f0 Update mmap.ipp
d35a6db8 Update mmap.ipp

git-subtree-dir: src/mio
git-subtree-split: 88e0263b075b832e78b9a36df58575a96ffe5e7d

README.md

@@ -181,6 +181,12 @@ using mmap_sink = mio::basic_mmap_sink<std::byte>;
 
 Though generally not needed, since mio maps users requested offsets to page boundaries, you can query the underlying system's page allocation granularity by invoking `mio::page_size()`, which is located in `mio/page.hpp`.
 
+### Single Header File 
+Mio can be added to your project as a single header file simply by including `\single_include\mio\mio.hpp`. Single header files can be regenerated at any time by running the `amalgamate.py` script within `\third_party`.  
+```
+python amalgamate.py -c config.json -s ../include
+```
+
 ## CMake
 As a header-only library, mio has no compiled components. Nevertheless, a [CMake](https://cmake.org/overview/) build system is provided to allow easy testing, installation, and subproject composition on many platforms and operating systems.
 
@@ -328,3 +334,4 @@ target_link_libraries( MyTarget PUBLIC <mio::mio | mio> )
 ```
 
 Note that, as a subproject, mio's tests and examples will not be built and CPack integration is deferred to the host project.
+

include/mio/detail/mmap.ipp

@@ -124,7 +124,7 @@ file_handle_type open_file(const String& path, const access_mode mode,
     return handle;
 }
 
-inline int64_t query_file_size(file_handle_type handle, std::error_code& error)
+inline size_t query_file_size(file_handle_type handle, std::error_code& error)
 {
     error.clear();
 #ifdef _WIN32
@@ -201,7 +201,7 @@ inline mmap_context memory_map(const file_handle_type file_handle, const int64_t
     }
 #endif
     mmap_context ctx;
-    ctx.data = mapping_start + offset - aligned_offset;
+    ctx.data = mapping_start + offset;
     ctx.length = length;
     ctx.mapped_length = length_to_map;
 #ifdef _WIN32
@@ -400,9 +400,10 @@ void basic_mmap<AccessMode, ByteT>::unmap()
     if(data_) { ::munmap(const_cast<pointer>(get_mapping_start()), mapped_length_); }
 #endif
 
-    // If file_handle_ was obtained by our opening it (when map is called with a path,
-    // rather than an existing file handle), we need to close it, otherwise it must not
-    // be closed as it may still be used outside this instance.
+    // If `file_handle_` was obtained by our opening it (when map is called with
+    // a path, rather than an existing file handle), we need to close it,
+    // otherwise it must not be closed as it may still be used outside this
+    // instance.
     if(is_handle_internal_)
     {
 #ifdef _WIN32

include/mio/mmap.hpp

@@ -76,15 +76,17 @@ struct basic_mmap
     // Points to the first requested byte, and not to the actual start of the mapping.
     pointer data_ = nullptr;
 
-    // Length, in bytes, requested by user, which may not be the length of the full
-    // mapping, and the entire length of the full mapping.
+    // Length--in bytes--requested by user (which may not be the length of the
+    // full mapping) and the length of the full mapping.
     size_type length_ = 0;
     size_type mapped_length_ = 0;
 
-    // Letting user map a file using both an existing file handle and a path introcudes
-    // On POSIX, we only need a file handle to create a mapping, while on Windows
-    // systems the file handle is necessary to retrieve a file mapping handle, but any
-    // subsequent operations on the mapped region must be done through the latter.
+    // Letting user map a file using both an existing file handle and a path
+    // introcudes some complexity (see `is_handle_internal_`).
+    // On POSIX, we only need a file handle to create a mapping, while on
+    // Windows systems the file handle is necessary to retrieve a file mapping
+    // handle, but any subsequent operations on the mapped region must be done
+    // through the latter.
     handle_type file_handle_ = INVALID_HANDLE_VALUE;
 #ifdef _WIN32
     handle_type file_mapping_handle_ = INVALID_HANDLE_VALUE;
@@ -94,7 +96,7 @@ struct basic_mmap
     // introcudes some complexity in that we must not close the file handle if
     // user provided it, but we must close it if we obtained it using the
     // provided path. For this reason, this flag is used to determine when to
-    // close file_handle_.
+    // close `file_handle_`.
     bool is_handle_internal_;
 
 public: