See comments inline...
> Module Name: othersrc
> Committed By: agc
> Date: Sun Nov 25 20:20:36 UTC 2012
>
> Modified Files:
> othersrc/external/bsd/mat/dist: mat.c mat.h
> othersrc/external/bsd/mat/libmat: shlib_version
>
> Log Message:
> Use mmap(2) to write files, where possible.
>
> Fallback to write(2) when not possible.
>
>
> To generate a diff of this commit:
> cvs rdiff -u -r1.5 -r1.6 othersrc/external/bsd/mat/dist/mat.c \
> othersrc/external/bsd/mat/dist/mat.h
> cvs rdiff -u -r1.1.1.1 -r1.2 othersrc/external/bsd/mat/libmat/shlib_version
>
> Please note that diffs are not public domain; they are subject to the
> copyright notices on the relevant files.
>
> Modified files:
>
> Index: othersrc/external/bsd/mat/dist/mat.c
> diff -u othersrc/external/bsd/mat/dist/mat.c:1.5
> othersrc/external/bsd/mat/dist/mat.c:1.6
> --- othersrc/external/bsd/mat/dist/mat.c:1.5 Sun Aug 12 01:42:24 2012
> +++ othersrc/external/bsd/mat/dist/mat.c Sun Nov 25 20:20:36 2012
> @@ -180,9 +180,44 @@ fillmeta(matent_t *ent, const char *f, s
> ent->meta.flags = st->st_flags;
> }
>
> +/* write to file */
> +static int
> +memwrite(FILE *fp, uint64_t off, const void *p, size_t size)
> +{
> + char *mapped;
> +
> + mapped = mmap(NULL, size, PROT_WRITE, MAP_SHARED, fileno(fp),
> (off_t)off);
> + if (mapped == MAP_FAILED) {
> + if (write(fileno(fp), p, size) != (ssize_t)size) {
> + fprintf(stderr, "short write %zu chars\n", size);
> + return 0;
> + }
> + } else {
> + lseek(fileno(fp), (off_t)(off + size - 1), SEEK_SET);
> + if (write(fileno(fp), "", 1) != 1) {
> + fprintf(stderr, "short write %" PRIu64 " chars\n",
> size);
> + return 0;
> + }
> + memcpy(mapped, p, size);
> + munmap(mapped, size);
> + }
> + return 1;
> +}
memwrite() can return with the file still being mapped (successful mmap(), then
a short write). Is that intended? No big problem if the calling program exits
when memwrite() returns 0, but I did not check that.
Then different formats are uses to print the size, "%u" in one case, "%" PRlu64
"" in the second case. Could be nicer if it was consistent, maybe.
> +
> +/* write to mat archive */
> +static int
> +archive_write(mat_t *mat, const void *p, size_t size)
> +{
> + if (memwrite(mat->fp, mat->off, p, size)) {
> + mat->off += size;
> + return 1;
> + }
> + return 0;
> +}
> +
> /* write the entry's meta information to the archive */
> static int
> -writemeta(int fd, matent_t *ent)
> +writemeta(mat_t *mat, matent_t *ent)
> {
> matent_t lent;
>
> @@ -199,7 +234,7 @@ writemeta(int fd, matent_t *ent)
> lent.meta.flags = local_htobe32(ent->meta.flags);
> lent.meta.linklen = local_htobe32(ent->meta.linklen);
> lent.meta.type = ent->meta.type;
> - return write(fd, &lent, sizeof(lent.meta)) == sizeof(lent.meta);
> + return archive_write(mat, &lent, sizeof(lent.meta)) ==
> sizeof(lent.meta);
> }
>
> /* read the entry's meta information from the archive */
> @@ -420,7 +455,10 @@ extract_file(mat_t *mat, extract_t *arch
> (void) fprintf(stderr, "can't create '%s'\n", name);
> return 0;
> }
> - write(fileno(fp), &archive->s[archive->off], ent->meta.size);
> + if (!memwrite(fp, 0, &archive->s[archive->off],
> ent->meta.size)) {
> + fprintf(stderr, "short write %" PRIu64 " chars\n",
> ent->meta.size);
> + return 0;
> + }
> tv[0].tv_sec = ent->meta.atime;
> tv[0].tv_usec = 0;
> tv[1].tv_sec = ent->meta.mtime;
> @@ -548,8 +586,8 @@ write_meta_info(mat_t *mat, matent_t *en
> (int)strlen(&f[matches[0].rm_eo]),
> &f[matches[0].rm_eo]) + 1;
> f = newpath;
> }
> - writemeta(fileno(mat->fp), ent);
> - write(fileno(mat->fp), f, ent->meta.namelen);
> + writemeta(mat, ent);
> + archive_write(mat, f, ent->meta.namelen);
> return 1;
> }
>
> @@ -629,13 +667,13 @@ mat_add(mat_t *mat, const char *f)
> return 0;
> }
> write_meta_info(mat, &ent, f);
> - write(fileno(mat->fp), mapped, (size_t)st.st_size);
> + archive_write(mat, mapped, (size_t)st.st_size);
> digest_update(ent.digest, mapped, (size_t)st.st_size);
> if (ent.meta.nlink > 1 && original) {
> /* multi-linked, and we're the primary */
> (void) memcpy(&mat->links[primary].digest, ent.digest,
> sizeof(ent.digest));
> }
> - write(fileno(mat->fp), ent.digest, sizeof(ent.digest));
> + archive_write(mat, ent.digest, sizeof(ent.digest));
> munmap(mapped, (size_t)st.st_size);
> (void) fclose(fp);
> break;
> @@ -643,10 +681,10 @@ mat_add(mat_t *mat, const char *f)
> /* store hardlink to primary */
> ent.meta.linklen = mat->links[primary].namelen;
> write_meta_info(mat, &ent, f);
> - write(fileno(mat->fp), mat->links[primary].name,
> (size_t)ent.meta.linklen);
> + archive_write(mat, mat->links[primary].name,
> (size_t)ent.meta.linklen);
> /* get digest from primary */
> (void) memcpy(ent.digest, mat->links[primary].digest,
> sizeof(ent.digest));
> - write(fileno(mat->fp), ent.digest, sizeof(ent.digest));
> + archive_write(mat, ent.digest, sizeof(ent.digest));
> break;
> case 'l':
> if ((cc = readlink(f, newpath, sizeof(newpath))) < 0) {
> @@ -656,9 +694,9 @@ mat_add(mat_t *mat, const char *f)
> newpath[cc] = 0x0;
> ent.meta.linklen = (uint32_t)(cc + 1);
> write_meta_info(mat, &ent, f);
> - write(fileno(mat->fp), newpath, (size_t)ent.meta.linklen);
> + archive_write(mat, newpath, (size_t)ent.meta.linklen);
> digest_update(ent.digest, (uint8_t *)newpath,
> (size_t)ent.meta.linklen);
> - write(fileno(mat->fp), ent.digest, sizeof(ent.digest));
> + archive_write(mat, ent.digest, sizeof(ent.digest));
> break;
> case 'b':
> case 'c':
> @@ -965,7 +1003,7 @@ mat_init(mat_t *mat, const char *f, cons
> mat->archive = st.st_ino;
> (void) memset(&header, 0x0, sizeof(header));
> header.magic = local_htobe32(MAT_MAGIC);
> - write(fileno(mat->fp), &header, sizeof(header));
> + archive_write(mat, &header, sizeof(header));
> return 1;
> }
> if ((mat->fp = fopen(f, "r")) == NULL) {
> Index: othersrc/external/bsd/mat/dist/mat.h
> diff -u othersrc/external/bsd/mat/dist/mat.h:1.5
> othersrc/external/bsd/mat/dist/mat.h:1.6
> --- othersrc/external/bsd/mat/dist/mat.h:1.5 Thu Oct 13 17:20:47 2011
> +++ othersrc/external/bsd/mat/dist/mat.h Sun Nov 25 20:20:36 2012
> @@ -64,9 +64,7 @@ typedef struct matmeta_t {
> uint32_t namelen; /* size of name */
> uint32_t linklen; /* size of link target */
> uint32_t flags; /* fs flags */
> -#if 0
> uint32_t xasize; /* extattr size */
> -#endif
> char type; /* single char type */
> } matmeta_t;
>
> @@ -75,9 +73,7 @@ typedef struct matent_t {
> matmeta_t meta; /* meta data */
> char *name; /* name of entry */
> uint8_t *data; /* associated data */
> -#if 0
> uint8_t *extattrs; /* extended attributes */
> -#endif
> uint8_t digest[MAT_DIGEST_LEN]; /* sha256 */
> } matent_t;
>
> @@ -99,6 +95,7 @@ typedef struct mat_t {
> const char *action; /* what action we're doing */
> FILE *fp; /* archive pointer */
> uint8_t *mapped; /* memory mapped archive */
> + uint64_t off; /* offset from start */
> size_t size; /* size of mmap */
> int verbose; /* be gobby */
> uint64_t archive; /* inode of the archive */
>
> Index: othersrc/external/bsd/mat/libmat/shlib_version
> diff -u othersrc/external/bsd/mat/libmat/shlib_version:1.1.1.1
> othersrc/external/bsd/mat/libmat/shlib_version:1.2
> --- othersrc/external/bsd/mat/libmat/shlib_version:1.1.1.1 Sat Jun 18
> 04:53:13 2011
> +++ othersrc/external/bsd/mat/libmat/shlib_version Sun Nov 25 20:20:36 2012
> @@ -1,2 +1,2 @@
> -major=0
> +major=1
> minor=0
>
