Refactor the command line interface

Select operation by its name instead of by number of the arguments.

1 files changed, 165 insertions, 22 deletions

diff --git a/src/resources.c b/src/resources.c
index 65b7f71..0829c7c 100644
--- a/src/resources.c
+++ b/src/resources.c
@@ -26,45 +26,188 @@
 
 #include "resources.h"
 
+#include "print.h"
+
+#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
-void
-resources_init(resources_t *const res)
+static void
+resources_init_for_backup(resources_backup_t *const res)
 {
     res->in_file = NULL;
     res->ref_file = NULL;
     res->out_file = NULL;
+
     res->in_buffer = NULL;
     res->ref_buffer = NULL;
     res->out_buffer = NULL;
 }
 
-void
-resources_free(resources_t *const res)
+static int
+resources_allocate_for_backup(const options_backup_t *const opts,
+                              resources_backup_t *const res)
 {
-    if (res->in_file != NULL) {
-        fclose(res->in_file);
-        res->in_file = NULL;
+    if ((res->in_file = fopen(opts->in_file_path, "r")) == NULL) {
+        print_error("cannot open input file: %s", strerror(errno));
+        return 1;
     }
-    if (res->ref_file != NULL) {
-        fclose(res->ref_file);
-        res->ref_file = NULL;
+
+    if ((res->ref_file = fopen(opts->ref_file_path, "r")) == NULL) {
+        print_error("cannot open reference file: %s", strerror(errno));
+        return 1;
     }
-    if (res->out_file != NULL) {
-        fclose(res->out_file);
-        res->out_file = NULL;
+
+    /* When backing up, the output file is truncated to hold the
+     * new data
+     */
+    if ((res->out_file = fopen(opts->out_file_path, "w+")) == NULL) {
+        print_error("cannot open output file: %s", strerror(errno));
+        return 1;
     }
-    if (res->in_buffer != NULL) {
-        free(res->in_buffer);
-        res->in_buffer = NULL;
+
+    /* The output buffer contains also the offsets */
+    res->out_buffer_size =
+        ((opts->buffer_size / opts->sector_size) * sizeof(uint64_t)) +
+        opts->buffer_size;
+
+    // TODO: separate function
+    if ((res->in_buffer = (char *)malloc(opts->buffer_size)) == NULL) {
+        print_error("cannot allocate buffer for input file data");
+        return 1;
+    } else if ((res->ref_buffer = (char *)malloc(opts->buffer_size)) == NULL) {
+        print_error("cannot allocate buffer for reference file data");
+        return 1;
+    } else if ((res->out_buffer = (char *)malloc(res->out_buffer_size)) ==
+               NULL) {
+        print_error("cannot allocate buffer for output file data");
+        return 1;
     }
-    if (res->ref_buffer != NULL) {
-        free(res->ref_buffer);
-        res->ref_buffer = NULL;
+
+    return 0;
+}
+
+static void
+resources_init_for_restore(resources_restore_t *const res)
+{
+    res->in_file = NULL;
+    res->out_file = NULL;
+
+    res->in_buffer = NULL;
+    res->out_buffer = NULL;
+}
+
+static int
+resources_allocate_for_restore(const options_restore_t *const opts,
+                               resources_restore_t *const res)
+{
+    if ((res->in_file = fopen(opts->in_file_path, "r")) == NULL) {
+        print_error("cannot open input file: %s", strerror(errno));
+        return 1;
     }
-    if (res->out_buffer != NULL) {
-        free(res->out_buffer);
-        res->out_buffer = NULL;
+
+    /* When restoring, the file must be opened for writing and not
+     * truncated
+     */
+    if ((res->out_file = fopen(opts->out_file_path, "r+")) == NULL) {
+        print_error("cannot open output file: %s", strerror(errno));
+        return 1;
     }
+
+    /* Allocate the buffer for data from the input file */
+    /* The input buffer contains also the offsets */
+    res->in_sector_size = sizeof(uint64_t) + opts->sector_size;
+    const size_t in_buffer_sector_count =
+        opts->buffer_size / res->in_sector_size;
+    res->in_buffer_size = in_buffer_sector_count * res->in_sector_size;
+
+    if ((res->in_buffer = (char *)malloc(res->in_buffer_size)) == NULL) {
+        print_error("cannot allocate buffer for input file data");
+        return 1;
+    }
+
+    return 0;
+}
+
+static void
+resources_close_file(FILE **const file)
+{
+    if (*file != NULL) {
+        fclose(*file);
+        *file = NULL;
+    }
+}
+
+static void
+resources_close_buffer(char **const buffer)
+{
+    if (*buffer != NULL) {
+        free(*buffer);
+        *buffer = NULL;
+    }
+}
+
+static void
+resources_free_backup(resources_backup_t *const res)
+{
+    resources_close_file(&(res->in_file));
+    resources_close_file(&(res->ref_file));
+    resources_close_file(&(res->out_file));
+
+    resources_close_buffer(&(res->in_buffer));
+    resources_close_buffer(&(res->ref_buffer));
+    resources_close_buffer(&(res->out_buffer));
+}
+
+static void
+resources_free_restore(resources_restore_t *const res)
+{
+    resources_close_file(&(res->in_file));
+    resources_close_file(&(res->out_file));
+
+    resources_close_buffer(&(res->in_buffer));
+    resources_close_buffer(&(res->out_buffer));
+}
+
+int
+resources_allocate(const options_t *const opts, resources_t *const res)
+{
+    res->operation_id = opts->operation_id;
+
+    if (res->operation_id == OPERATION_ID_BACKUP) {
+        resources_init_for_backup(&(res->res.backup));
+        return resources_allocate_for_backup(&(opts->op.backup),
+                                             &(res->res.backup));
+    } else if (res->operation_id == OPERATION_ID_RESTORE) {
+        resources_init_for_restore(&(res->res.restore));
+        return resources_allocate_for_restore(&(opts->op.restore),
+                                              &(res->res.restore));
+    }
+
+    return 0;
+}
+
+const resources_backup_t *
+resources_get_for_backup(const resources_t *const res)
+{
+    return &(res->res.backup);
+}
+
+const resources_restore_t *
+resources_get_for_restore(const resources_t *const res)
+{
+    return &(res->res.restore);
+}
+
+void
+resources_free(resources_t *const res)
+{
+    if (res->operation_id == OPERATION_ID_BACKUP) {
+        resources_free_backup(&(res->res.backup));
+    } else if (res->operation_id == OPERATION_ID_RESTORE) {
+        resources_free_restore(&(res->res.restore));
+    }
+
+    res->operation_id = OPERATION_ID_UNKNOWN;
 }