Release 0.13.0

native/test_atomic_file.c

@@ -0,0 +1,101 @@
+#define _DEFAULT_SOURCE
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+static bool interrupt_write, short_write, fail_write, fail_sync, fail_rename, fail_commit_sync;
+static unsigned directory_syncs;
+static ssize_t fixture_write(int fd, const void *data, size_t n) {
+    if (interrupt_write) {
+        interrupt_write = false;
+        errno = EINTR;
+        return -1;
+    }
+    if (fail_write) {
+        errno = ENOSPC;
+        return -1;
+    }
+    return write(fd, data, short_write && n > 2 ? 2 : n);
+}
+static int fixture_sync(int fd) {
+    struct stat info;
+    assert(!fstat(fd, &info));
+    if (S_ISDIR(info.st_mode)) {
+        directory_syncs++;
+        if (fail_commit_sync && directory_syncs == 2) {
+            errno = EIO;
+            return -1;
+        }
+    } else if (fail_sync) {
+        errno = EIO;
+        return -1;
+    }
+    return fsync(fd);
+}
+static int fixture_rename(int from, const char *a, int to, const char *b) {
+    if (fail_rename) {
+        errno = EACCES;
+        return -1;
+    }
+    return renameat(from, a, to, b);
+}
+#define ATOMIC_WRITE fixture_write
+#define ATOMIC_SYNC fixture_sync
+#define ATOMIC_RENAME fixture_rename
+#include "atomic_file.h"
+static void contents(const char *path, const char *expected) {
+    char data[64] = {0};
+    int fd = open(path, O_RDONLY);
+    assert(fd >= 0);
+    assert(read(fd, data, sizeof(data) - 1) == (ssize_t)strlen(expected));
+    close(fd);
+    assert(!strcmp(data, expected));
+}
+int main(void) {
+    char directory[] = "/tmp/hyperdrm-save-XXXXXX";
+    assert(mkdtemp(directory));
+    char path[128], stale[128], link[128];
+    snprintf(path, sizeof(path), "%s/settings.json", directory);
+    snprintf(stale, sizeof(stale), "%s/settings.json.tmp", directory);
+    snprintf(link, sizeof(link), "%s/link", directory);
+    int fd = open(stale, O_CREAT | O_WRONLY, 0600);
+    assert(fd >= 0);
+    close(fd);
+    assert(atomic_replace(path, "old", 3) == SAVE_DURABLE);
+    interrupt_write = short_write = true;
+    assert(atomic_replace(path, "partial writes handled", 22) == SAVE_DURABLE);
+    contents(path, "partial writes handled");
+    short_write = false;
+    fail_write = true;
+    assert(atomic_replace(path, "new", 3) == SAVE_UNCHANGED);
+    fail_write = false;
+    contents(path, "partial writes handled");
+    fail_sync = true;
+    assert(atomic_replace(path, "new", 3) == SAVE_UNCHANGED);
+    fail_sync = false;
+    fail_rename = true;
+    assert(atomic_replace(path, "new", 3) == SAVE_UNCHANGED);
+    fail_rename = false;
+    contents(path, "partial writes handled");
+    directory_syncs = 0;
+    fail_commit_sync = true;
+    assert(atomic_replace(path, "committed", 9) == SAVE_COMMITTED);
+    contents(path, "committed");
+    fail_commit_sync = false;
+    assert(!symlink(path, link));
+    assert(atomic_replace(link, "bad", 3) == SAVE_UNCHANGED);
+    contents(path, "committed");
+    struct stat info;
+    assert(!stat(path, &info) && (info.st_mode & 0777) == 0600);
+    assert(!access(stale, F_OK));
+    unlink(link);
+    unlink(path);
+    unlink(stale);
+    assert(!rmdir(directory));
+    puts("PASS: interrupted/partial writes, write/sync/rename failures, atomic replacement, commit "
+         "durability, private permissions, symlinks and stale files");
+}