From 8bd3d51b23e328e91c209dbebe8cfe002b0b0042 Mon Sep 17 00:00:00 2001 From: laforge Date: Tue, 12 Sep 2006 17:37:00 +0000 Subject: move to new directory git-svn-id: https://svn.openpcd.org:2342/trunk@193 6dc7ffe9-61d6-0310-9af1-9938baff3ed1 --- host/zebvty/buffer.c | 460 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 460 insertions(+) create mode 100644 host/zebvty/buffer.c (limited to 'host/zebvty/buffer.c') diff --git a/host/zebvty/buffer.c b/host/zebvty/buffer.c new file mode 100644 index 0000000..0610ebb --- /dev/null +++ b/host/zebvty/buffer.c @@ -0,0 +1,460 @@ +/* + * Buffering of output and input. + * Copyright (C) 1998 Kunihiro Ishiguro + * + * This file is part of GNU Zebra. + * + * GNU Zebra 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 2, or (at your + * option) any later version. + * + * GNU Zebra 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 GNU Zebra; see the file COPYING. If not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + */ + +#include +#include +#include +#include +#include +#include +#include + +#include "buffer.h" +#include "vty.h" + +/* Buffer master. */ +struct buffer { + /* Data list. */ + struct buffer_data *head; + struct buffer_data *tail; + + /* Size of each buffer_data chunk. */ + size_t size; +}; + +/* Data container. */ +struct buffer_data { + struct buffer_data *next; + + /* Location to add new data. */ + size_t cp; + + /* Pointer to data not yet flushed. */ + size_t sp; + + /* Actual data stream (variable length). */ + unsigned char data[0]; /* real dimension is buffer->size */ +}; + +/* It should always be true that: 0 <= sp <= cp <= size */ + +/* Default buffer size (used if none specified). It is rounded up to the + next page boundery. */ +#define BUFFER_SIZE_DEFAULT 4096 + +#define BUFFER_DATA_FREE(D) free((D)) + +/* Make new buffer. */ +struct buffer *buffer_new(size_t size) +{ + struct buffer *b; + + b = calloc(1, sizeof(struct buffer)); + + if (size) + b->size = size; + else { + static size_t default_size; + if (!default_size) { + long pgsz = sysconf(_SC_PAGESIZE); + default_size = + ((((BUFFER_SIZE_DEFAULT - 1) / pgsz) + 1) * pgsz); + } + b->size = default_size; + } + + return b; +} + +/* Free buffer. */ +void buffer_free(struct buffer *b) +{ + buffer_reset(b); + free(b); +} + +/* Make string clone. */ +char *buffer_getstr(struct buffer *b) +{ + size_t totlen = 0; + struct buffer_data *data; + char *s; + char *p; + + for (data = b->head; data; data = data->next) + totlen += data->cp - data->sp; + if (!(s = malloc(totlen + 1))) + return NULL; + p = s; + for (data = b->head; data; data = data->next) { + memcpy(p, data->data + data->sp, data->cp - data->sp); + p += data->cp - data->sp; + } + *p = '\0'; + return s; +} + +/* Return 1 if buffer is empty. */ +int buffer_empty(struct buffer *b) +{ + return (b->head == NULL); +} + +/* Clear and free all allocated data. */ +void buffer_reset(struct buffer *b) +{ + struct buffer_data *data; + struct buffer_data *next; + + for (data = b->head; data; data = next) { + next = data->next; + BUFFER_DATA_FREE(data); + } + b->head = b->tail = NULL; +} + +/* Add buffer_data to the end of buffer. */ +static struct buffer_data *buffer_add(struct buffer *b) +{ + struct buffer_data *d; + + d = malloc(offsetof(struct buffer_data, data[b->size])); + if (!d) + return NULL; + d->cp = d->sp = 0; + d->next = NULL; + + if (b->tail) + b->tail->next = d; + else + b->head = d; + b->tail = d; + + return d; +} + +/* Write data to buffer. */ +void buffer_put(struct buffer *b, const void *p, size_t size) +{ + struct buffer_data *data = b->tail; + const char *ptr = p; + + /* We use even last one byte of data buffer. */ + while (size) { + size_t chunk; + + /* If there is no data buffer add it. */ + if (data == NULL || data->cp == b->size) + data = buffer_add(b); + + chunk = + ((size <= + (b->size - data->cp)) ? size : (b->size - data->cp)); + memcpy((data->data + data->cp), ptr, chunk); + size -= chunk; + ptr += chunk; + data->cp += chunk; + } +} + +/* Insert character into the buffer. */ +void buffer_putc(struct buffer *b, u_char c) +{ + buffer_put(b, &c, 1); +} + +/* Put string to the buffer. */ +void buffer_putstr(struct buffer *b, const char *c) +{ + buffer_put(b, c, strlen(c)); +} + +/* Keep flushing data to the fd until the buffer is empty or an error is + encountered or the operation would block. */ +buffer_status_t buffer_flush_all(struct buffer *b, int fd) +{ + buffer_status_t ret; + struct buffer_data *head; + size_t head_sp; + + if (!b->head) + return BUFFER_EMPTY; + head_sp = (head = b->head)->sp; + /* Flush all data. */ + while ((ret = buffer_flush_available(b, fd)) == BUFFER_PENDING) { + if ((b->head == head) && (head_sp == head->sp) + && (errno != EINTR)) + /* No data was flushed, so kernel buffer must be full. */ + return ret; + head_sp = (head = b->head)->sp; + } + + return ret; +} + +#if 0 +/* Flush enough data to fill a terminal window of the given scene (used only + by vty telnet interface). */ +buffer_status_t +buffer_flush_window(struct buffer * b, int fd, int width, int height, + int erase_flag, int no_more_flag) +{ + int nbytes; + int iov_alloc; + int iov_index; + struct iovec *iov; + struct iovec small_iov[3]; + char more[] = " --More-- "; + char erase[] = + { 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, + ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', + 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08 + }; + struct buffer_data *data; + int column; + + if (!b->head) + return BUFFER_EMPTY; + + if (height < 1) { + zlog_warn + ("%s called with non-positive window height %d, forcing to 1", + __func__, height); + height = 1; + } else if (height >= 2) + height--; + if (width < 1) { + zlog_warn + ("%s called with non-positive window width %d, forcing to 1", + __func__, width); + width = 1; + } + + /* For erase and more data add two to b's buffer_data count. */ + if (b->head->next == NULL) { + iov_alloc = sizeof(small_iov) / sizeof(small_iov[0]); + iov = small_iov; + } else { + iov_alloc = ((height * (width + 2)) / b->size) + 10; + iov = XMALLOC(MTYPE_TMP, iov_alloc * sizeof(*iov)); + } + iov_index = 0; + + /* Previously print out is performed. */ + if (erase_flag) { + iov[iov_index].iov_base = erase; + iov[iov_index].iov_len = sizeof erase; + iov_index++; + } + + /* Output data. */ + column = 1; /* Column position of next character displayed. */ + for (data = b->head; data && (height > 0); data = data->next) { + size_t cp; + + cp = data->sp; + while ((cp < data->cp) && (height > 0)) { + /* Calculate lines remaining and column position after displaying + this character. */ + if (data->data[cp] == '\r') + column = 1; + else if ((data->data[cp] == '\n') || (column == width)) { + column = 1; + height--; + } else + column++; + cp++; + } + iov[iov_index].iov_base = (char *)(data->data + data->sp); + iov[iov_index++].iov_len = cp - data->sp; + data->sp = cp; + + if (iov_index == iov_alloc) + /* This should not ordinarily happen. */ + { + iov_alloc *= 2; + if (iov != small_iov) { + zlog_warn("%s: growing iov array to %d; " + "width %d, height %d, size %lu", + __func__, iov_alloc, width, height, + (u_long) b->size); + iov = + XREALLOC(MTYPE_TMP, iov, + iov_alloc * sizeof(*iov)); + } else { + /* This should absolutely never occur. */ + zlog_err + ("%s: corruption detected: iov_small overflowed; " + "head %p, tail %p, head->next %p", + __func__, b->head, b->tail, b->head->next); + iov = + XMALLOC(MTYPE_TMP, + iov_alloc * sizeof(*iov)); + memcpy(iov, small_iov, sizeof(small_iov)); + } + } + } + + /* In case of `more' display need. */ + if (b->tail && (b->tail->sp < b->tail->cp) && !no_more_flag) { + iov[iov_index].iov_base = more; + iov[iov_index].iov_len = sizeof more; + iov_index++; + } +#ifdef IOV_MAX + /* IOV_MAX are normally defined in , Posix.1g. + example: Solaris2.6 are defined IOV_MAX size at 16. */ + { + struct iovec *c_iov = iov; + nbytes = 0; /* Make sure it's initialized. */ + + while (iov_index > 0) { + int iov_size; + + iov_size = + ((iov_index > IOV_MAX) ? IOV_MAX : iov_index); + if ((nbytes = writev(fd, c_iov, iov_size)) < 0) { + zlog_warn("%s: writev to fd %d failed: %s", + __func__, fd, safe_strerror(errno)); + break; + } + + /* move pointer io-vector */ + c_iov += iov_size; + iov_index -= iov_size; + } + } +#else /* IOV_MAX */ + if ((nbytes = writev(fd, iov, iov_index)) < 0) + zlog_warn("%s: writev to fd %d failed: %s", + __func__, fd, safe_strerror(errno)); +#endif /* IOV_MAX */ + + /* Free printed buffer data. */ + while (b->head && (b->head->sp == b->head->cp)) { + struct buffer_data *del; + if (!(b->head = (del = b->head)->next)) + b->tail = NULL; + BUFFER_DATA_FREE(del); + } + + if (iov != small_iov) + XFREE(MTYPE_TMP, iov); + + return (nbytes < 0) ? BUFFER_ERROR : + (b->head ? BUFFER_PENDING : BUFFER_EMPTY); +} +#endif + +/* This function (unlike other buffer_flush* functions above) is designed +to work with non-blocking sockets. It does not attempt to write out +all of the queued data, just a "big" chunk. It returns 0 if it was +able to empty out the buffers completely, 1 if more flushing is +required later, or -1 on a fatal write error. */ +buffer_status_t buffer_flush_available(struct buffer * b, int fd) +{ + +/* These are just reasonable values to make sure a significant amount of +data is written. There's no need to go crazy and try to write it all +in one shot. */ +#ifdef IOV_MAX +#define MAX_CHUNKS ((IOV_MAX >= 16) ? 16 : IOV_MAX) +#else +#define MAX_CHUNKS 16 +#endif +#define MAX_FLUSH 131072 + + struct buffer_data *d; + size_t written; + struct iovec iov[MAX_CHUNKS]; + size_t iovcnt = 0; + size_t nbyte = 0; + + for (d = b->head; d && (iovcnt < MAX_CHUNKS) && (nbyte < MAX_FLUSH); + d = d->next, iovcnt++) { + iov[iovcnt].iov_base = d->data + d->sp; + nbyte += (iov[iovcnt].iov_len = d->cp - d->sp); + } + + if (!nbyte) + /* No data to flush: should we issue a warning message? */ + return BUFFER_EMPTY; + + /* only place where written should be sign compared */ + if ((ssize_t) (written = writev(fd, iov, iovcnt)) < 0) { + if (ERRNO_IO_RETRY(errno)) + /* Calling code should try again later. */ + return BUFFER_PENDING; + return BUFFER_ERROR; + } + + /* Free printed buffer data. */ + while (written > 0) { + struct buffer_data *d; + if (!(d = b->head)) + break; + if (written < d->cp - d->sp) { + d->sp += written; + return BUFFER_PENDING; + } + + written -= (d->cp - d->sp); + if (!(b->head = d->next)) + b->tail = NULL; + BUFFER_DATA_FREE(d); + } + + return b->head ? BUFFER_PENDING : BUFFER_EMPTY; + +#undef MAX_CHUNKS +#undef MAX_FLUSH +} + +buffer_status_t +buffer_write(struct buffer * b, int fd, const void *p, size_t size) +{ + ssize_t nbytes; + +#if 0 + /* Should we attempt to drain any previously buffered data? This could help reduce latency in pushing out the data if we are stuck in a long-running thread that is preventing the main select loop from calling the flush thread... */ + + if (b->head && (buffer_flush_available(b, fd) == BUFFER_ERROR)) + return BUFFER_ERROR; +#endif + if (b->head) + /* Buffer is not empty, so do not attempt to write the new data. */ + nbytes = 0; + else if ((nbytes = write(fd, p, size)) < 0) { + if (ERRNO_IO_RETRY(errno)) + nbytes = 0; + else + return BUFFER_ERROR; + } + /* Add any remaining data to the buffer. */ + { + size_t written = nbytes; + if (written < size) + buffer_put(b, ((const char *)p) + written, + size - written); + } + return b->head ? BUFFER_PENDING : BUFFER_EMPTY; +} -- cgit v1.2.3