1 #ifndef chrqueue_h 2 #define chrqueue_h 3 4 /* 5 * Copyright (c) 2000, 2001, 2002, 2003, 2004 by Martin C. Shepherd. 6 * 7 * All rights reserved. 8 * 9 * Permission is hereby granted, free of charge, to any person obtaining a 10 * copy of this software and associated documentation files (the 11 * "Software"), to deal in the Software without restriction, including 12 * without limitation the rights to use, copy, modify, merge, publish, 13 * distribute, and/or sell copies of the Software, and to permit persons 14 * to whom the Software is furnished to do so, provided that the above 15 * copyright notice(s) and this permission notice appear in all copies of 16 * the Software and that both the above copyright notice(s) and this 17 * permission notice appear in supporting documentation. 18 * 19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 20 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 21 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT 22 * OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 23 * HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL 24 * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING 25 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, 26 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION 27 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 28 * 29 * Except as contained in this notice, the name of a copyright holder 30 * shall not be used in advertising or otherwise to promote the sale, use 31 * or other dealings in this Software without prior written authorization 32 * of the copyright holder. 33 */ 34 35 /*----------------------------------------------------------------------- 36 * This module implements a queue of characters to be processed in some 37 * way. It is used by gl_get_line() to maintain a queue of characters 38 * to be sent to a remote terminal. Characters are recorded in a 39 * dynamically extensible list of fixed sized buffers. 40 */ 41 42 typedef struct GlCharQueue GlCharQueue; 43 44 /* 45 * Create a new character queue. 46 */ 47 GlCharQueue *_new_GlCharQueue(void); 48 49 /* 50 * Delete a redundant character queue. 51 */ 52 GlCharQueue *_del_GlCharQueue(GlCharQueue *cq); 53 54 /* 55 * Append an array of n characters to a character queue. 56 */ 57 int _glq_append_chars(GlCharQueue *cq, const char *chars, int n, 58 GlWriteFn *write_fn, void *data); 59 60 /* 61 * Clear a character queue. 62 */ 63 void _glq_empty_queue(GlCharQueue *cq); 64 65 /* 66 * Return a count of the number of characters in the queue. 67 */ 68 int _glq_char_count(GlCharQueue *cq); 69 70 /* 71 * A structure of the following type is used by _glq_peek_chars() to 72 * return characters at the start of the queue. 73 */ 74 typedef struct { 75 const char *buff; /* A pointer to the first undeleted byte in the */ 76 /* first buffer of the queue. */ 77 int nbuff; /* The number of characters in buff[] */ 78 } GlCharQueueBuff; 79 80 /* 81 * Enumerator values of the following type are returned by 82 * _glq_flush_queue() to indicate the status of the flush operation. 83 */ 84 typedef enum { 85 GLQ_FLUSH_DONE, /* The flush operation completed successfully */ 86 GLQ_FLUSH_AGAIN, /* The flush operation couldn't be completed on this */ 87 /* call. Call this function again when the output */ 88 /* channel can accept further output. */ 89 GLQ_FLUSH_ERROR /* Unrecoverable error. */ 90 } GlqFlushState; 91 92 /* 93 * Transfer as much of the contents of a character queue to an output 94 * channel as possible, returning before the queue is empty if the 95 * write_fn() callback says that it can't currently write anymore. 96 */ 97 GlqFlushState _glq_flush_queue(GlCharQueue *cq, GlWriteFn *write_fn, 98 void *data); 99 100 /* 101 * Provide information about the last error that occurred while calling 102 * any of the above functions. 103 */ 104 const char *_glq_last_error(GlCharQueue *cq); 105 106 #endif 107