Add Splitter VFD to library.

* "Simultaneous and equivalent" Read-Write and Write-Only channels for
  file I/O.
* Only supports drivers with the H5FD_FEAT_DEFAULT_VFD_COMPATIBLE flag for
  now, preventing issues with multi-file drivers.

Add Mirror VFD to library.

* Write-only operations over a network.
* Uses TCP/IP sockets.
* Server and auxiliary server-shutdown programs provided in a new directory,
  `utils/mirror_vfd`.
* Automated testing via loopback ("remote" of localhost).

1 files changed, 225 insertions, 0 deletions

diff --git a/utils/mirror_vfd/mirror_remote.c b/utils/mirror_vfd/mirror_remote.c
new file mode 100644
index 0000000..81a3625
--- /dev/null
+++ b/utils/mirror_vfd/mirror_remote.c
@@ -0,0 +1,225 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/* Common operations for "remote" processes for the Mirror VFD.
+ *
+ * Jacob Smith, 2020-03-06
+ */
+
+#include "mirror_remote.h"
+
+#ifdef H5_HAVE_MIRROR_VFD
+
+
+/* ---------------------------------------------------------------------------
+ * Function:    mirror_log
+ *
+ * Purpose:     Write message to the logging stream/file.
+ *              If logging info pointer is NULL, uses logging defaults.
+ * ----------------------------------------------------------------------------
+ */
+void
+mirror_log(struct mirror_log_info *info,
+           unsigned int            level,
+           const char             *format,
+           ...)
+{
+    FILE *stream = MIRROR_LOG_DEFAULT_STREAM;
+    unsigned int verbosity = MIRROR_LOG_DEFAULT_VERBOSITY;
+    hbool_t      custom = FALSE;
+
+    if (info != NULL && info->magic == MIRROR_LOG_INFO_MAGIC) {
+        stream = info->stream;
+        verbosity = info->verbosity;
+        custom = TRUE;
+    }
+
+    if (level == V_NONE) {
+        return;
+    }
+    else
+    if (level <= verbosity) {
+        if (custom == TRUE && info->prefix[0] != '\0') {
+            HDfprintf(stream, "%s", info->prefix);
+        }
+
+        switch (level) {
+        case (V_ERR) :
+            HDfprintf(stream, "ERROR ");
+            break;
+        case (V_WARN) :
+            HDfprintf(stream, "WARNING ");
+            break;
+        default:
+            break;
+        }
+
+        if (format != NULL) {
+            va_list args;
+            HDva_start(args, format);
+            HDvfprintf(stream, format, args);
+            HDva_end(args);
+        }
+
+        HDfprintf(stream, "\n");
+        HDfflush(stream);
+    } /* end if sufficiently verbose to print */
+} /* end mirror_log() */
+
+
+/* ---------------------------------------------------------------------------
+ * Function:    session_log_bytes
+ *
+ * Purpose:     "Pretty-print" raw binary data to logging stream/file.
+ *              If info pointer is NULL, uses logging defaults.
+ * ----------------------------------------------------------------------------
+ */
+void
+mirror_log_bytes(struct mirror_log_info *info,
+                 unsigned int            level,
+                 size_t                  n_bytes,
+                 const unsigned char    *buf)
+{
+    FILE *stream = MIRROR_LOG_DEFAULT_STREAM;
+    unsigned int verbosity = MIRROR_LOG_DEFAULT_VERBOSITY;
+
+    if (buf == NULL) {
+        return;
+    }
+
+    if (info != NULL && info->magic == MIRROR_LOG_INFO_MAGIC) {
+        stream = info->stream;
+        verbosity = info->verbosity;
+    }
+
+    if (level <= verbosity) {
+        size_t bytes_written = 0;
+        const unsigned char *b = NULL;
+
+        /* print whole lines */
+        while ((n_bytes - bytes_written) >= 32) {
+            b = buf + bytes_written; /* point to region in buffer */
+            HDfprintf(stream,
+                    "%04zX  %02X%02X%02X%02X %02X%02X%02X%02X" \
+                          " %02X%02X%02X%02X %02X%02X%02X%02X" \
+                          " %02X%02X%02X%02X %02X%02X%02X%02X" \
+                          " %02X%02X%02X%02X %02X%02X%02X%02X\n",
+                    bytes_written,
+                    b[0], b[1], b[2], b[3],   b[4], b[5], b[6], b[7],
+                    b[8], b[9], b[10],b[11],  b[12],b[13],b[14],b[15],
+                    b[16],b[17],b[18],b[19],  b[20],b[21],b[22],b[23],
+                    b[24],b[25],b[26],b[27],  b[28],b[29],b[30],b[31]);
+            bytes_written += 32;
+        }
+
+        /* start partial line */
+        if (n_bytes > bytes_written) {
+            HDfprintf(stream, "%04zX ", bytes_written);
+        }
+
+        /* partial line blocks */
+        while ((n_bytes - bytes_written) >= 4) {
+            HDfprintf(stream, " %02X%02X%02X%02X",
+                    buf[bytes_written],   buf[bytes_written+1],
+                    buf[bytes_written+2], buf[bytes_written+3]);
+            bytes_written += 4;
+        }
+
+        /* block separator before partial block */
+        if (n_bytes > bytes_written) {
+            HDfprintf(stream, " ");
+        }
+
+        /* partial block individual bytes */
+        while (n_bytes > bytes_written) {
+            HDfprintf(stream, "%02X", buf[bytes_written++]);
+        }
+
+        /* end partial line */
+        HDfprintf(stream, "\n");
+    } /* end if suitably verbose to log */
+} /* end mirror_log_bytes() */
+
+
+/* ---------------------------------------------------------------------------
+ * Function:    mirror_log_init
+ *
+ * Purpose:     Prepare a loginfo_t structure for use.
+ *
+ * Return:      Success: Pointer to newly-ceated info.
+ *              Failure: NULL. Either unable to allocate or cannot open file.
+ * ----------------------------------------------------------------------------
+ */
+loginfo_t *
+mirror_log_init(char *path, char *prefix, unsigned int verbosity)
+{
+    loginfo_t *info = NULL;
+
+    info = (loginfo_t *)HDmalloc(sizeof(loginfo_t));
+    if (info != NULL) {
+        info->magic = MIRROR_LOG_INFO_MAGIC;
+        info->verbosity = verbosity;
+        info->stream = MIRROR_LOG_DEFAULT_STREAM;
+        info->prefix[0] = '\0';
+
+        if (prefix && *prefix) {
+            HDstrncpy(info->prefix, prefix, MIRROR_LOG_PREFIX_MAX);
+        }
+
+        if (path && *path) {
+            FILE *f = NULL;
+            f = HDfopen(path, "w");
+            if (NULL == f) {
+                HDfprintf(MIRROR_LOG_DEFAULT_STREAM,
+                        "WARN custom logging path could not be opened: %s\n",
+                        path);
+                info->magic += 1;
+                HDfree(info);
+            }
+            else {
+                info->stream = f;
+            }
+        }
+
+    } /* end if able to allocate */
+
+    return info;
+} /* end mirror_log_init() */
+
+
+/* ---------------------------------------------------------------------------
+ * Function:    mirror_log_term
+ *
+ * Purpose:     Shut down and clean up a loginfo_t structure.
+ *
+ * Return:      Success: SUCCEED. Resources released.
+ *              Failure: FAIL.    Indeterminite state.
+ * ----------------------------------------------------------------------------
+ */
+herr_t
+mirror_log_term(loginfo_t *info)
+{
+    if (info == NULL || info->magic != MIRROR_LOG_INFO_MAGIC) {
+        return FAIL;
+    }
+    if (info->stream != stderr || info->stream != stdout) {
+        if (HDfclose(info->stream) < 0) {
+            return FAIL;
+        }
+    }
+    info->magic += 1;
+    HDfree(info);
+    return SUCCEED;
+} /* end mirror_log_term() */
+
+#endif /* H5_HAVE_MIRROR_VFD */
+