From b8d0f83e6cea9640a7ee4402c163ad812237355d Mon Sep 17 00:00:00 2001
From: Laurent Bercot <ska-skaware@skarnet.org>
Date: Sun, 10 Dec 2023 11:48:01 +0000
Subject:  Initial commit

Signed-off-by: Laurent Bercot <ska@appnovation.com>
---
 src/cache/dcache_save.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 src/cache/dcache_save.c

(limited to 'src/cache/dcache_save.c')

diff --git a/src/cache/dcache_save.c b/src/cache/dcache_save.c
new file mode 100644
index 0000000..7277771
--- /dev/null
+++ b/src/cache/dcache_save.c
@@ -0,0 +1,73 @@
+/* ISC license. */
+
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include <skalibs/posixplz.h>
+#include <skalibs/uint16.h>
+#include <skalibs/uint64.h>
+#include <skalibs/buffer.h>
+#include <skalibs/tai.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/skamisc.h>
+#include <skalibs/gensetdyn.h>
+
+#include <shibari/dcache.h>
+
+static int write_node_iter (void *data, void *aux)
+{
+  dcache_node_t *y = data ;
+  buffer *b = aux ;
+  char pack[TAI_PACK * 2 + 4] ;
+  tai_pack(pack, tain_secp(&y->entry)) ;
+  tai_pack(pack + TAI_PACK, tain_secp(&y->expire)) ;
+  uint16_pack(pack + TAI_PACK * 2, y->key.len) ;
+  uint16_pack(pack + TAI_PACK * 2 + 2, y->datalen) ;
+  if (buffer_put(b, pack, TAI_PACK * 2 + 4) == -1) return 0 ;
+  if (buffer_put(b, y->key.s, y->key.len + y->datalen) == -1) return 0 ;
+  if (buffer_put(b, "", 1) == -1) return 0 ;
+  return 1 ;
+}
+
+static inline int dcache_save_to_buffer (dcache_t const *z, buffer *b)
+{
+  char pack[16] ;
+  if (buffer_puts(b, DCACHE_MAGIC) == -1) return 0 ;
+  uint64_pack_big(pack, z->size) ;
+  uint64_pack_big(pack + 8, z->motion) ;
+  if (buffer_put(b, pack, 16) < 16) return 0 ;
+
+ /* XXX: can gensetdyn_iter blow up the stack if z->storage is huge? */
+  if (gensetdyn_iter_nocancel((gensetdyn *)&z->storage, gensetdyn_n(&z->storage), &write_node_iter, b) < gensetdyn_n(&z->storage)) return 0 ;
+
+  return buffer_flush(b) ;
+}
+
+#define N 8192
+
+int dcache_save (dcache_t const *z, char const *file)
+{
+  size_t len = strlen(file) ;
+  int fd ;
+  buffer b ;
+  char buf[N] ;
+  char tmp[len + 20] ;
+  memcpy(tmp, file, len) ;
+  memcpy(tmp + len, ":dcache_save:XXXXXX", 20) ;
+  fd = mkstemp(tmp) ;
+  if (fd == -1) return 0 ;
+  buffer_init(&b, &buffer_write, fd, buf, N) ;
+  if (!dcache_save_to_buffer(z, &b) || fsync(fd) < 0) goto err2 ;
+  fd_close(fd) ;
+  if (rename(tmp, file) == -1) goto err1 ;
+  return 1 ;
+
+ err2:
+  fd_close(fd) ;
+ err1:
+  unlink_void(tmp) ;
+  return 0 ;
+}
-- 
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