diff options
| -rw-r--r-- | ChangeLog | 4 | ||||
| -rw-r--r-- | Src/input.c | 24 | ||||
| -rw-r--r-- | configure.ac | 59 |
3 files changed, 86 insertions, 1 deletions
@@ -1,5 +1,9 @@ 2022-04-28 Bart Schaefer <schaefer@zsh.org> + * 50133 (Bart, PWS, Jun-ichi): Src/input.c, configure.ac: when + lseek(2) is available, use it to check for and rewind read-ahead + for more efficient line-buffered input. + * 50126: Etc/BUGS, Src/exec.c: Fix multios in current-shell "exec" * 50101: Src/Modules/system.c: sysread -o with param matches doc diff --git a/Src/input.c b/Src/input.c index c59232681..9898a7177 100644 --- a/Src/input.c +++ b/Src/input.c @@ -217,12 +217,34 @@ shinbufrestore(void) static int shingetchar(void) { - int nread; + int nread, rsize = isset(SHINSTDIN) ? 1 : SHINBUFSIZE; if (shinbufptr < shinbufendptr) return STOUC(*shinbufptr++); shinbufreset(); +#ifdef USE_LSEEK + if (rsize == 1 && lseek(SHIN, 0, SEEK_CUR) != (off_t)-1) + rsize = SHINBUFSIZE; + if (rsize > 1) { + do { + errno = 0; + nread = read(SHIN, shinbuffer, rsize); + } while (nread < 0 && errno == EINTR); + if (nread <= 0) + return -1; + if (isset(SHINSTDIN) && + (shinbufendptr = memchr(shinbuffer, '\n', nread))) { + shinbufendptr++; + rsize = (shinbufendptr - shinbuffer); + if (nread > rsize && + lseek(SHIN, -(nread - rsize), SEEK_CUR) < 0) + zerr("lseek(%d, %d): %e", SHIN, -(nread - rsize), errno); + } else + shinbufendptr = shinbuffer + nread; + return STOUC(*shinbufptr++); + } +#endif for (;;) { errno = 0; nread = read(SHIN, shinbufendptr, 1); diff --git a/configure.ac b/configure.ac index 8bba78c56..c72148d06 100644 --- a/configure.ac +++ b/configure.ac @@ -2210,6 +2210,65 @@ if test x$zsh_cv_sys_fifo = xyes; then fi dnl ----------- +dnl check that lseek() correctly reports seekability. +dnl ----------- +AC_CACHE_CHECK(if lseek() correctly reports seekability, +zsh_cv_sys_lseek, +[AC_RUN_IFELSE([AC_LANG_SOURCE([[ +#include <stdio.h> +#include <sys/types.h> +#include <fcntl.h> +#include <unistd.h> +#include <sys/socket.h> +#include <sys/stat.h> +int main() { + int pipefd[2], fd; + off_t ret; + char* tmpfile = "seekfiletest.tmp"; + if ((fd = open(tmpfile, O_CREAT, S_IRUSR)) < 0) { + fprintf(stderr, "creating file failed\n"); + return 1; + } + ret = lseek(fd, 0, SEEK_CUR); + close(fd); + unlink(tmpfile); + if (ret == (off_t)-1) { + fprintf(stderr, "lseek on regular file failed\n"); + return 1; + } + if (pipe(pipefd) < 0) { + fprintf(stderr, "creating pipe failed\n"); + return 1; + } + write(pipefd[1], "abcdefgh", 8); + ret = lseek(pipefd[0], 0, SEEK_CUR); + close(pipefd[0]); + close(pipefd[1]); + if (ret != (off_t)-1) { + fprintf(stderr, "lseek on pipe succeeded\n"); + return 1; + } + if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) { + fprintf(stderr, "creating UNIX domain socket failed\n"); + return 1; + } + ret = lseek(fd, 0, SEEK_CUR); + close(fd); + if (ret != (off_t)-1) { + fprintf(stderr, "lseek on UNIX domain socket succeeded\n"); + return 1; + } + return 0; +} +]])],[zsh_cv_sys_lseek=yes],[zsh_cv_sys_lseek=no],[zsh_cv_sys_lseek=yes]) +]) +AH_TEMPLATE([USE_LSEEK], +[Define to 1 if lseek() can be used for SHIN.]) +if test x$zsh_cv_sys_lseek = xyes; then + AC_DEFINE(USE_LSEEK) +fi + +dnl ----------- dnl test for whether link() works dnl for instance, BeOS R4.51 doesn't support hard links yet dnl ----------- |