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Diffstat (limited to '')
-rw-r--r-- | src/viewer/growbuf.c | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/src/viewer/growbuf.c b/src/viewer/growbuf.c new file mode 100644 index 0000000..9b97536 --- /dev/null +++ b/src/viewer/growbuf.c @@ -0,0 +1,300 @@ +/* + Internal file viewer for the Midnight Commander + Function for work with growing bufers + + Copyright (C) 1994-2022 + Free Software Foundation, Inc. + + Written by: + Miguel de Icaza, 1994, 1995, 1998 + Janne Kukonlehto, 1994, 1995 + Jakub Jelinek, 1995 + Joseph M. Hinkle, 1996 + Norbert Warmuth, 1997 + Pavel Machek, 1998 + Roland Illig <roland.illig@gmx.de>, 2004, 2005 + Slava Zanko <slavazanko@google.com>, 2009 + Andrew Borodin <aborodin@vmail.ru>, 2009, 2014 + Ilia Maslakov <il.smind@gmail.com>, 2009 + + This file is part of the Midnight Commander. + + The Midnight Commander is free software: you can redistribute it + and/or modify it under the terms of the GNU General Public License as + published by the Free Software Foundation, either version 3 of the License, + or (at your option) any later version. + + The Midnight Commander is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <config.h> +#include <errno.h> + +#include "lib/global.h" +#include "lib/vfs/vfs.h" +#include "lib/util.h" +#include "lib/widget.h" /* D_NORMAL */ + +#include "internal.h" + +/* Block size for reading files in parts */ +#define VIEW_PAGE_SIZE ((size_t) 8192) + +/*** global variables ****************************************************************************/ + +/*** file scope macro definitions ****************************************************************/ + +/*** file scope type declarations ****************************************************************/ + +/*** file scope variables ************************************************************************/ + +/*** file scope functions ************************************************************************/ +/* --------------------------------------------------------------------------------------------- */ + +/* --------------------------------------------------------------------------------------------- */ +/*** public functions ****************************************************************************/ +/* --------------------------------------------------------------------------------------------- */ + +void +mcview_growbuf_init (WView * view) +{ + view->growbuf_in_use = TRUE; + view->growbuf_blockptr = g_ptr_array_new (); + view->growbuf_lastindex = VIEW_PAGE_SIZE; + view->growbuf_finished = FALSE; +} + +/* --------------------------------------------------------------------------------------------- */ + +void +mcview_growbuf_done (WView * view) +{ + view->growbuf_finished = TRUE; + + if (view->datasource == DS_STDIO_PIPE) + { + mc_pclose (view->ds_stdio_pipe, NULL); + view->ds_stdio_pipe = NULL; + } + else /* view->datasource == DS_VFS_PIPE */ + { + (void) mc_close (view->ds_vfs_pipe); + view->ds_vfs_pipe = -1; + } +} + +/* --------------------------------------------------------------------------------------------- */ + +void +mcview_growbuf_free (WView * view) +{ + g_assert (view->growbuf_in_use); + + g_ptr_array_foreach (view->growbuf_blockptr, (GFunc) g_free, NULL); + + (void) g_ptr_array_free (view->growbuf_blockptr, TRUE); + + view->growbuf_blockptr = NULL; + view->growbuf_in_use = FALSE; +} + +/* --------------------------------------------------------------------------------------------- */ + +off_t +mcview_growbuf_filesize (WView * view) +{ + g_assert (view->growbuf_in_use); + + if (view->growbuf_blockptr->len == 0) + return 0; + else + return ((off_t) view->growbuf_blockptr->len - 1) * VIEW_PAGE_SIZE + view->growbuf_lastindex; +} + +/* --------------------------------------------------------------------------------------------- */ +/** Copies the output from the pipe to the growing buffer, until either + * the end-of-pipe is reached or the interval [0..ofs) of the growing + * buffer is completely filled. + */ + +void +mcview_growbuf_read_until (WView * view, off_t ofs) +{ + gboolean short_read = FALSE; + + g_assert (view->growbuf_in_use); + + if (view->growbuf_finished) + return; + + while (mcview_growbuf_filesize (view) < ofs || short_read) + { + ssize_t nread = 0; + byte *p; + size_t bytesfree; + + if (view->growbuf_lastindex == VIEW_PAGE_SIZE) + { + /* Append a new block to the growing buffer */ + byte *newblock = g_try_malloc (VIEW_PAGE_SIZE); + if (newblock == NULL) + return; + + g_ptr_array_add (view->growbuf_blockptr, newblock); + view->growbuf_lastindex = 0; + } + + p = (byte *) g_ptr_array_index (view->growbuf_blockptr, + view->growbuf_blockptr->len - 1) + view->growbuf_lastindex; + + bytesfree = VIEW_PAGE_SIZE - view->growbuf_lastindex; + + if (view->datasource == DS_STDIO_PIPE) + { + mc_pipe_t *sp = view->ds_stdio_pipe; + GError *error = NULL; + + if (bytesfree > MC_PIPE_BUFSIZE) + bytesfree = MC_PIPE_BUFSIZE; + + sp->out.len = bytesfree; + sp->err.len = MC_PIPE_BUFSIZE; + + mc_pread (sp, &error); + + if (error != NULL) + { + mcview_show_error (view, error->message); + g_error_free (error); + mcview_growbuf_done (view); + return; + } + + if (view->pipe_first_err_msg && sp->err.len > 0) + { + /* ignore possible following errors */ + /* reset this flag before call of mcview_show_error() to break + * endless recursion: mcview_growbuf_read_until() -> mcview_show_error() -> + * MSG_DRAW -> mcview_display() -> mcview_get_byte() -> mcview_growbuf_read_until() + */ + view->pipe_first_err_msg = FALSE; + + mcview_show_error (view, sp->err.buf); + + /* when switch from parse to raw mode and back, + * do not close the already closed pipe (see call to mcview_growbuf_done below). + * return from here since (sp == view->ds_stdio_pipe) would now be invalid. + * NOTE: this check was removed by ticket #4103 but the above call to + * mcview_show_error triggers the stdio pipe handle to be closed: + * mcview_close_datasource -> mcview_growbuf_done + */ + if (view->ds_stdio_pipe == NULL) + return; + } + + if (sp->out.len > 0) + { + memmove (p, sp->out.buf, sp->out.len); + nread = sp->out.len; + } + else if (sp->out.len == MC_PIPE_STREAM_EOF || sp->out.len == MC_PIPE_ERROR_READ) + { + if (sp->out.len == MC_PIPE_ERROR_READ) + { + char *err_msg; + + err_msg = g_strdup_printf (_("Failed to read data from child stdout:\n%s"), + unix_error_string (sp->out.error)); + mcview_show_error (view, err_msg); + g_free (err_msg); + } + + /* when switch from parse to raw mode and back, + * do not close the already closed pipe after following loop: + * mcview_growbuf_read_until() -> mcview_show_error() -> + * MSG_DRAW -> mcview_display() -> mcview_get_byte() -> mcview_growbuf_read_until() + */ + mcview_growbuf_done (view); + + mcview_display (view); + return; + } + } + else + { + g_assert (view->datasource == DS_VFS_PIPE); + do + { + nread = mc_read (view->ds_vfs_pipe, p, bytesfree); + } + while (nread == -1 && errno == EINTR); + + if (nread <= 0) + { + mcview_growbuf_done (view); + return; + } + } + short_read = ((size_t) nread < bytesfree); + view->growbuf_lastindex += nread; + } +} + +/* --------------------------------------------------------------------------------------------- */ + +gboolean +mcview_get_byte_growing_buffer (WView * view, off_t byte_index, int *retval) +{ + char *p; + + g_assert (view->growbuf_in_use); + + if (retval != NULL) + *retval = -1; + + if (byte_index < 0) + return FALSE; + + p = mcview_get_ptr_growing_buffer (view, byte_index); + if (p == NULL) + return FALSE; + + if (retval != NULL) + *retval = (unsigned char) (*p); + + return TRUE; +} + +/* --------------------------------------------------------------------------------------------- */ + +char * +mcview_get_ptr_growing_buffer (WView * view, off_t byte_index) +{ + off_t pageno, pageindex; + + g_assert (view->growbuf_in_use); + + if (byte_index < 0) + return NULL; + + pageno = byte_index / VIEW_PAGE_SIZE; + pageindex = byte_index % VIEW_PAGE_SIZE; + + mcview_growbuf_read_until (view, byte_index + 1); + if (view->growbuf_blockptr->len == 0) + return NULL; + if (pageno < (off_t) view->growbuf_blockptr->len - 1) + return ((char *) g_ptr_array_index (view->growbuf_blockptr, pageno) + pageindex); + if (pageno == (off_t) view->growbuf_blockptr->len - 1 + && pageindex < (off_t) view->growbuf_lastindex) + return ((char *) g_ptr_array_index (view->growbuf_blockptr, pageno) + pageindex); + return NULL; +} + +/* --------------------------------------------------------------------------------------------- */ |