From 354bb40e75d94466e91fe6960523612c9d17ccfb Mon Sep 17 00:00:00 2001
From: Karen Arutyunov <karen@codesynthesis.com>
Date: Thu, 2 Nov 2017 23:11:29 +0300
Subject: Add implementation

---
 mysql/mysys/my_read.c | 107 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100644 mysql/mysys/my_read.c

(limited to 'mysql/mysys/my_read.c')

diff --git a/mysql/mysys/my_read.c b/mysql/mysys/my_read.c
new file mode 100644
index 0000000..c80ad1c
--- /dev/null
+++ b/mysql/mysys/my_read.c
@@ -0,0 +1,107 @@
+/* Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
+
+#include "mysys_priv.h"
+#include "my_sys.h"
+#include "mysys_err.h"
+#include <my_base.h>
+#include <errno.h>
+#include "my_thread_local.h"
+
+/*
+  Read a chunk of bytes from a file with retry's if needed
+
+  The parameters are:
+    File descriptor
+    Buffer to hold at least Count bytes
+    Bytes to read
+    Flags on what to do on error
+
+    Return:
+      -1 on error
+      0  if flag has bits MY_NABP or MY_FNABP set
+      N  number of bytes read.
+*/
+
+size_t my_read(File Filedes, uchar *Buffer, size_t Count, myf MyFlags)
+{
+  size_t readbytes, save_count;
+  DBUG_ENTER("my_read");
+  DBUG_PRINT("my",("fd: %d  Buffer: %p  Count: %lu  MyFlags: %d",
+                   Filedes, Buffer, (ulong) Count, MyFlags));
+  save_count= Count;
+
+  for (;;)
+  {
+    errno= 0;					/* Linux, Windows don't reset this on EOF/success */
+#ifdef _WIN32
+    readbytes= my_win_read(Filedes, Buffer, Count);
+#else
+    readbytes= read(Filedes, Buffer, Count);
+#endif
+    DBUG_EXECUTE_IF ("simulate_file_read_error",
+                     {
+                       errno= ENOSPC;
+                       readbytes= (size_t) -1;
+                       DBUG_SET("-d,simulate_file_read_error");
+                       DBUG_SET("-d,simulate_my_b_fill_error");
+                     });
+
+    if (readbytes != Count)
+    {
+      set_my_errno(errno);
+      if (errno == 0 || (readbytes != (size_t) -1 &&
+                         (MyFlags & (MY_NABP | MY_FNABP))))
+        set_my_errno(HA_ERR_FILE_TOO_SHORT);
+      DBUG_PRINT("warning",("Read only %d bytes off %lu from %d, errno: %d",
+                            (int) readbytes, (ulong) Count, Filedes,
+                            my_errno()));
+
+      if ((readbytes == 0 || (int) readbytes == -1) && errno == EINTR)
+      {  
+        DBUG_PRINT("debug", ("my_read() was interrupted and returned %ld",
+                             (long) readbytes));
+        continue;                              /* Interrupted */
+      }
+
+      if (MyFlags & (MY_WME | MY_FAE | MY_FNABP))
+      {
+        char errbuf[MYSYS_STRERROR_SIZE];
+        if (readbytes == (size_t) -1)
+          my_error(EE_READ, MYF(0), my_filename(Filedes),
+                   my_errno(), my_strerror(errbuf, sizeof(errbuf), my_errno()));
+        else if (MyFlags & (MY_NABP | MY_FNABP))
+          my_error(EE_EOFERR, MYF(0), my_filename(Filedes),
+                   my_errno(), my_strerror(errbuf, sizeof(errbuf), my_errno()));
+      }
+      if (readbytes == (size_t) -1 ||
+          ((MyFlags & (MY_FNABP | MY_NABP)) && !(MyFlags & MY_FULL_IO)))
+        DBUG_RETURN(MY_FILE_ERROR);	/* Return with error */
+      if (readbytes != (size_t) -1 && (MyFlags & MY_FULL_IO))
+      {
+        Buffer+= readbytes;
+        Count-= readbytes;
+        continue;
+      }
+    }
+
+    if (MyFlags & (MY_NABP | MY_FNABP))
+      readbytes= 0;			/* Ok on read */
+    else if (MyFlags & MY_FULL_IO)
+      readbytes= save_count;
+    break;
+  }
+  DBUG_RETURN(readbytes);
+} /* my_read */
-- 
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