slbt_store_archive(): initial implementation.

1 files changed, 143 insertions, 0 deletions

diff --git a/src/arbits/slbt_archive_store.c b/src/arbits/slbt_archive_store.c
new file mode 100644
index 0000000..d8281b0
--- /dev/null
+++ b/src/arbits/slbt_archive_store.c
@@ -0,0 +1,143 @@
+/*******************************************************************/
+/*  slibtool: a skinny libtool implementation, written in C        */
+/*  Copyright (C) 2016--2024  SysDeer Technologies, LLC            */
+/*  Released under the Standard MIT License; see COPYING.SLIBTOOL. */
+/*******************************************************************/
+
+#include <time.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <limits.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <sys/stat.h>
+
+#include <slibtool/slibtool.h>
+#include <slibtool/slibtool_arbits.h>
+#include "slibtool_ar_impl.h"
+#include "slibtool_driver_impl.h"
+#include "slibtool_errinfo_impl.h"
+
+/****************************************************/
+/* As elsewhere in slibtool, file-system operations */
+/* utilizie the _at variants of the relevant posix  */
+/* interfaces. In the case of archives, that means  */
+/* passing dctx->fdctx->fdcwd as the _fdat_ param,  */
+/* where dctx is the driver context which was used  */
+/* with slbt_get_archive_ctx().                     */
+/************************************************** */
+
+#define PPRIX64 "%"PRIx64
+
+int slbt_store_archive(
+	struct slbt_archive_ctx * arctx,
+	const char *              path,
+	mode_t                    mode)
+{
+	const struct slbt_driver_ctx *  dctx;
+	struct stat                     st;
+	int                             fdat;
+	int                             fdtmp;
+	char *                          mark;
+	char *                          slash;
+	size_t                          buflen;
+	size_t                          nbytes;
+	ssize_t                         written;
+	char                            buf[PATH_MAX];
+
+	/* init dctx */
+	if (!(dctx = slbt_get_archive_ictx(arctx)->dctx))
+		return -1;
+
+	/* validation */
+	if (strlen(path) >= PATH_MAX)
+		return SLBT_CUSTOM_ERROR(
+			dctx,
+			SLBT_ERR_FLOW_ERROR);
+
+	/**************************************************/
+	/* create temporary file in the target directory  */
+	/*                                                */
+	/* the tmpfile name pattern involes the inode     */
+	/* of the target directory, a local stack address */
+	/* in the calling thread, the current time, and   */
+	/* finally the pid of the current process.        */
+	/**************************************************/
+
+	memset(buf,0,sizeof(buf));
+	strcpy(buf,path);
+
+	fdat = slbt_driver_fdcwd(dctx);
+
+	mark = (slash = strrchr(buf,'/'))
+		? slash : buf;
+
+	if (slash) {
+		*++mark = '\0';
+
+		if (fstatat(fdat,buf,&st,0) < 0)
+			return SLBT_SYSTEM_ERROR(
+				dctx,0);
+	} else {
+		if (fstatat(fdat,".",&st,0) < 0)
+			return SLBT_SYSTEM_ERROR(
+				dctx,0);
+	}
+
+	buflen = sizeof(buf) - (mark - buf);
+	nbytes = snprintf(
+		mark,
+		buflen,
+		".slibtool.tmpfile"
+		".inode."PPRIX64
+		".time."PPRIX64
+		".salt.%p"
+		".pid.%d"
+		".tmp",
+		st.st_ino,
+		time(0),&buf,
+		getpid());
+
+	if (nbytes >= buflen)
+		return SLBT_CUSTOM_ERROR(
+			dctx,
+			SLBT_ERR_FLOW_ERROR);
+
+	if ((fdtmp = openat(fdat,buf,O_WRONLY|O_CREAT|O_EXCL,mode)) < 0)
+		return SLBT_SYSTEM_ERROR(dctx,0);
+
+	/* set archive size */
+	if (ftruncate(fdtmp,arctx->map->map_size) < 0)
+		return SLBT_SYSTEM_ERROR(dctx,0);
+
+	/* write archive */
+	mark   = arctx->map->map_addr;
+	nbytes = arctx->map->map_size;
+
+	for (; nbytes; ) {
+		written = write(fdtmp,mark,nbytes);
+
+		while ((written < 0) && (errno == EINTR))
+			written = write(fdtmp,mark,nbytes);
+
+		if (written < 0) {
+			unlinkat(fdat,buf,0);
+			return SLBT_SYSTEM_ERROR(dctx,0);
+		};
+
+		nbytes -= written;
+		mark   += written;
+	}
+
+	/* finalize (atomically) */
+	if (renameat(fdat,buf,fdat,path) < 0) {
+		unlinkat(fdat,buf,0);
+		return SLBT_SYSTEM_ERROR(dctx,0);
+	}
+
+	/* yay */
+	return 0;
+}