1 /* 2 * Copyright (c) 2009-2012, Pieter Noordhuis <pcnoordhuis at gmail dot com> 3 * Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions are met: 8 * 9 * * Redistributions of source code must retain the above copyright notice, 10 * this list of conditions and the following disclaimer. 11 * * Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * * Neither the name of Redis nor the names of its contributors may be used 15 * to endorse or promote products derived from this software without 16 * specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 32 #ifndef __REDIS_RIO_H 33 #define __REDIS_RIO_H 34 35 #include <stdio.h> 36 #include <stdint.h> 37 #include "sds.h" 38 39 struct _rio { 40 /* Backend functions. 41 * Since this functions do not tolerate short writes or reads the return 42 * value is simplified to: zero on error, non zero on complete success. */ 43 size_t (*read)(struct _rio *, void *buf, size_t len); 44 size_t (*write)(struct _rio *, const void *buf, size_t len); 45 off_t (*tell)(struct _rio *); 46 int (*flush)(struct _rio *); 47 /* The update_cksum method if not NULL is used to compute the checksum of 48 * all the data that was read or written so far. The method should be 49 * designed so that can be called with the current checksum, and the buf 50 * and len fields pointing to the new block of data to add to the checksum 51 * computation. */ 52 void (*update_cksum)(struct _rio *, const void *buf, size_t len); 53 54 /* The current checksum */ 55 uint64_t cksum; 56 57 /* number of bytes read or written */ 58 size_t processed_bytes; 59 60 /* maximum single read or write chunk size */ 61 size_t max_processing_chunk; 62 63 /* Backend-specific vars. */ 64 union { 65 /* In-memory buffer target. */ 66 struct { 67 sds ptr; 68 off_t pos; 69 } buffer; 70 /* Stdio file pointer target. */ 71 struct { 72 FILE *fp; 73 off_t buffered; /* Bytes written since last fsync. */ 74 off_t autosync; /* fsync after 'autosync' bytes written. */ 75 } file; 76 /* Multiple FDs target (used to write to N sockets). */ 77 struct { 78 int *fds; /* File descriptors. */ 79 int *state; /* Error state of each fd. 0 (if ok) or errno. */ 80 int numfds; 81 off_t pos; 82 sds buf; 83 } fdset; 84 } io; 85 }; 86 87 typedef struct _rio rio; 88 89 /* The following functions are our interface with the stream. They'll call the 90 * actual implementation of read / write / tell, and will update the checksum 91 * if needed. */ 92 93 static inline size_t rioWrite(rio *r, const void *buf, size_t len) { 94 while (len) { 95 size_t bytes_to_write = (r->max_processing_chunk && r->max_processing_chunk < len) ? r->max_processing_chunk : len; 96 if (r->update_cksum) r->update_cksum(r,buf,bytes_to_write); 97 if (r->write(r,buf,bytes_to_write) == 0) 98 return 0; 99 buf = (char*)buf + bytes_to_write; 100 len -= bytes_to_write; 101 r->processed_bytes += bytes_to_write; 102 } 103 return 1; 104 } 105 106 static inline size_t rioRead(rio *r, void *buf, size_t len) { 107 while (len) { 108 size_t bytes_to_read = (r->max_processing_chunk && r->max_processing_chunk < len) ? r->max_processing_chunk : len; 109 if (r->read(r,buf,bytes_to_read) == 0) 110 return 0; 111 if (r->update_cksum) r->update_cksum(r,buf,bytes_to_read); 112 buf = (char*)buf + bytes_to_read; 113 len -= bytes_to_read; 114 r->processed_bytes += bytes_to_read; 115 } 116 return 1; 117 } 118 119 static inline off_t rioTell(rio *r) { 120 return r->tell(r); 121 } 122 123 static inline int rioFlush(rio *r) { 124 return r->flush(r); 125 } 126 127 void rioInitWithFile(rio *r, FILE *fp); 128 void rioInitWithBuffer(rio *r, sds s); 129 void rioInitWithFdset(rio *r, int *fds, int numfds); 130 131 size_t rioWriteBulkCount(rio *r, char prefix, int count); 132 size_t rioWriteBulkString(rio *r, const char *buf, size_t len); 133 size_t rioWriteBulkLongLong(rio *r, long long l); 134 size_t rioWriteBulkDouble(rio *r, double d); 135 136 void rioGenericUpdateChecksum(rio *r, const void *buf, size_t len); 137 void rioSetAutoSync(rio *r, off_t bytes); 138 139 #endif 140