REFARRAY: New referenced array object

This object allows creation the arrays
with the reference count. Usefull when
there are many instances of some object
have to reference dynamically allocated array
which is common for all these instances.

In case of ELAPI the event object
keeps a referecne to the common array
of the sinks in the fail over order.

We decided that it will be a common object
not specific only to ELAPI.

All the review concerns related to this
object have been addressed in this patch.
It also has been moved to the common area.

1 files changed, 294 insertions, 0 deletions

diff --git a/common/refarray/ref_array.c b/common/refarray/ref_array.c
new file mode 100644
index 000000000..d33a16b4f
--- /dev/null
+++ b/common/refarray/ref_array.c
@@ -0,0 +1,294 @@
+/*
+    REF ARRAY
+
+    Implementation of the dynamic array with reference count.
+
+    Copyright (C) Dmitri Pal <dpal@redhat.com> 2009
+
+    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; either version 3 of the License, or
+    (at your option) any later version.
+    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, see <http://www.gnu.org/licenses/>.
+*/
+
+#define _GNU_SOURCE
+#include <errno.h>  /* for errors */
+#include <stdint.h>
+#include <malloc.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "ref_array.h"
+#include "config.h"
+#include "trace.h"
+
+/* The structure used in referenced array */
+struct ref_array {
+    void *storage;      /* The storage buffer */
+    size_t elsize;      /* Size of one element in the buffer */
+    uint32_t size;      /* Size of the storage in items */
+    uint32_t grow_by;   /* What increment use to reallocate memory */
+    uint32_t len;       /* Number of the elements in the array */
+    uint32_t refcount;  /* Reference count */
+    ref_array_fn cb;    /* Cleanup callback */
+    void *cb_data;      /* Caller's callback data */
+};
+
+/****************************************************/
+/* INTERNAL FUNCTIONS                               */
+/****************************************************/
+static int ref_array_grow(struct ref_array *ra)
+{
+    int error = EOK;
+    void *newbuf = NULL;
+
+    TRACE_FLOW_STRING("ref_array_grow", "Entry");
+
+    TRACE_INFO_NUMBER("Current length: ", ra->len);
+    TRACE_INFO_NUMBER("Current size: ", ra->size);
+
+    /* Grow buffer if needed */
+    newbuf = realloc(ra->storage, (ra->size + ra->grow_by) * ra->elsize);
+    if (newbuf == NULL) {
+        TRACE_ERROR_NUMBER("Failed to allocate memory.", ENOMEM);
+        return ENOMEM;
+    }
+
+    ra->storage = newbuf;
+    ra->size += ra->grow_by;
+
+    TRACE_INFO_NUMBER("Final size: ", ra->size);
+    TRACE_FLOW_NUMBER("elapi_grow_data. Exit. Returning", error);
+    return error;
+
+}
+
+
+/****************************************************/
+/* PUBLIC FUNCTIONS                                 */
+/****************************************************/
+
+/* Create referenced array */
+int ref_array_create(struct ref_array **ra,
+                     size_t elemsz,
+                     uint32_t grow_by,
+                     ref_array_fn cb,
+                     void *data)
+{
+    struct ref_array *new_ra = NULL;
+
+    TRACE_FLOW_STRING("ref_array_create", "Entry");
+
+    if (!ra) {
+        TRACE_ERROR_NUMBER("Uninitialized argument.", EINVAL);
+        return EINVAL;
+    }
+
+    if ((!elemsz) || (!grow_by)) {
+        TRACE_ERROR_NUMBER("Invalid argument.", EINVAL);
+        return EINVAL;
+    }
+
+    new_ra = (struct ref_array *)malloc(sizeof(struct ref_array));
+
+    if (!new_ra) {
+        TRACE_ERROR_NUMBER("Failed to allocate memory.", ENOMEM);
+        return ENOMEM;
+    }
+
+    new_ra->storage = NULL;
+    new_ra->elsize = elemsz;
+    new_ra->size = 0;
+    new_ra->grow_by = grow_by;
+    new_ra->len = 0;
+    new_ra->refcount = 1;
+    new_ra->cb = cb;
+    new_ra->cb_data = data;
+
+    *ra = new_ra;
+
+    TRACE_FLOW_STRING("ref_array_create", "Exit");
+    return EOK;
+}
+
+/* Get new reference to an array */
+struct ref_array *ref_array_getref(struct ref_array *ra)
+{
+    TRACE_FLOW_STRING("ref_array_getref", "Entry");
+
+    /* Check if array is not NULL */
+    if (ra) {
+        TRACE_INFO_NUMBER("Increasing reference count. Current: ", ra->refcount);
+        /* Increase reference count */
+        ra->refcount++;
+        TRACE_INFO_NUMBER("Increased reference count. New: ", ra->refcount);
+
+    }
+    else {
+        TRACE_ERROR_STRING("Uninitialized array.", "Returning NULL");
+    }
+
+    TRACE_FLOW_STRING("ref_array_getref", "Exit");
+    return ra;
+}
+
+/* Delete the array */
+void ref_array_destroy(struct ref_array *ra)
+{
+    int idx;
+
+    TRACE_FLOW_STRING("ref_array_destroy", "Entry");
+
+    /* Check if array is not NULL */
+    if (!ra) {
+        TRACE_ERROR_STRING("Uninitialized array.", "Coding error???");
+        return;
+    }
+
+    TRACE_INFO_NUMBER("Current reference count: ", ra->refcount);
+    if (ra->refcount) {
+        /* Decrease reference count */
+        ra->refcount--;
+        if (ra->refcount == 0) {
+            TRACE_INFO_NUMBER("It is time to delete array. Count:", ra->refcount);
+            if (ra->cb) {
+                for (idx = 0; idx < ra->len; idx++) {
+                    ra->cb((unsigned char *)(ra->storage) + idx * ra->elsize,
+                            REF_ARRAY_DESTROY, ra->cb_data);
+                }
+            }
+            free(ra->storage);
+            free(ra);
+        }
+    }
+    else {
+        /* Should never be here...
+         * This can happen if the caller by mistake would try to
+         * destroy the object from within the callback. Brrr....
+         */
+        TRACE_ERROR_STRING("Reference count is 0.", "Coding error???");
+    }
+
+    TRACE_FLOW_STRING("ref_array_destroy", "Exit");
+}
+
+/* Add new element to the array */
+int ref_array_append(struct ref_array *ra, void *element)
+{
+    int error = EOK;
+
+    TRACE_FLOW_STRING("ref_array_append", "Entry");
+    if ((!ra) || (!element)) {
+        TRACE_ERROR_NUMBER("Uninitialized argument.", EINVAL);
+        return EINVAL;
+    }
+
+    /* Do we have enough room for a new element? */
+    if (ra->size == ra->len) {
+        error = ref_array_grow(ra);
+        if (error) {
+            TRACE_ERROR_NUMBER("Failed to grow array.", error);
+            return EINVAL;
+        }
+    }
+
+    /* Copy element */
+    memcpy((unsigned char *)(ra->storage) + ra->len * ra->elsize,
+           element,
+           ra->elsize);
+
+    ra->len++;
+
+    TRACE_FLOW_STRING("ref_array_append", "Exit");
+    return error;
+}
+
+/* Get element */
+void *ref_array_get(struct ref_array *ra, uint32_t idx, void *acptr)
+{
+    TRACE_FLOW_STRING("ref_array_get", "Entry");
+
+    if (!ra) {
+        TRACE_ERROR_STRING("Uninitialized argument.", "");
+        return NULL;
+    }
+
+    if (idx >= ra->len) {
+        TRACE_ERROR_NUMBER("Invalid idx.", idx);
+        return NULL;
+    }
+
+    TRACE_INFO_NUMBER("Index: ", idx);
+
+    if (acptr) {
+
+        TRACE_INFO_STRING("Copying data.", "");
+        memcpy(acptr,
+               (unsigned char *)(ra->storage) + idx * ra->elsize,
+               ra->elsize);
+
+    }
+
+    TRACE_FLOW_STRING("ref_array_get returning internal storage", "Exit");
+    return (unsigned char *)(ra->storage) + idx * ra->elsize;
+}
+
+
+/* Get length */
+int ref_array_getlen(struct ref_array *ra, uint32_t *len)
+{
+    TRACE_FLOW_STRING("ref_array_getlen", "Entry");
+
+    if ((!ra) || (!len)) {
+        TRACE_ERROR_STRING("Uninitialized argument.", "");
+        return EINVAL;
+    }
+
+    *len = ra->len;
+
+    TRACE_FLOW_STRING("ref_array_getlen", "Exit");
+    return EOK;
+}
+
+/* Alternative function to get length */
+uint32_t ref_array_len(struct ref_array *ra)
+{
+    TRACE_FLOW_STRING("ref_array_len", "Entry");
+
+    if (!ra) {
+        TRACE_ERROR_STRING("Uninitialized argument.", "");
+        errno = EINVAL;
+        return 0;
+    }
+
+    TRACE_FLOW_STRING("ref_array_len", "Exit");
+    return ra->len;
+}
+
+
+/* Debug function */
+void ref_array_debug(struct ref_array *ra)
+{
+    int i,j;
+
+    printf("\nARRAY DUMP START\n");
+    printf("Length = %u\n", ra->len);
+    printf("Size = %u\n", ra->size);
+    printf("Element = %u\n", (unsigned int)(ra->elsize));
+    printf("Grow by = %u\n", ra->grow_by);
+    printf("Count = %u\n", ra->refcount);
+    printf("ARRAY:\n");
+    for (i = 0; i < ra->len; i++)  {
+        for (j = 0; j < ra->elsize; j++) {
+            printf("%x", *((unsigned char *)(ra->storage) + i * ra->elsize + j));
+        }
+        printf("\n%s\n", *((char **)((unsigned char *)(ra->storage) + i * ra->elsize)));
+    }
+    printf("\nARRAY DUMP END\n\n");
+}