X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=src%2Frrd_open.c;h=e83918454cad9e3bee9ac37b819ca6e5ce401cdc;hb=b9c1a336b13d8093b9841848cbed687a6e01a5c3;hp=07ee109abc6ae6544dc2797dc621c17279a9760e;hpb=264a94560ae83c638e05b0b93b85fd6285b07dac;p=rrdtool.git diff --git a/src/rrd_open.c b/src/rrd_open.c index 07ee109..e839184 100644 --- a/src/rrd_open.c +++ b/src/rrd_open.c @@ -66,9 +66,21 @@ #include "unused.h" #define MEMBLK 8192 +/* DEBUG 2 prints information obtained via mincore(2) */ +// #define DEBUG 2 +/* do not calculate exact madvise hints but assume 1 page for headers and + * set DONTNEED for the rest, which is assumed to be data */ +//#define ONE_PAGE 1 +/* Avoid calling madvise on areas that were already hinted. May be benefical if + * your syscalls are very slow */ +#define CHECK_MADVISE_OVERLAPS 1 + #ifdef HAVE_MMAP +/* the cast to void* is there to avoid this warning seen on ia64 with certain + versions of gcc: 'cast increases required alignment of target type' +*/ #define __rrd_read(dst, dst_t, cnt) \ - (dst) = (dst_t*) (data + offset); \ + (dst) = (dst_t*)(void*) (data + offset); \ offset += sizeof(dst_t) * (cnt) #else #define __rrd_read(dst, dst_t, cnt) \ @@ -79,8 +91,40 @@ offset += read (rrd_file->fd, dst, sizeof(dst_t)*(cnt)) #endif -/* open a database file, return its header and an open filehandle */ -/* positioned to the first cdp in the first rra */ +/* next page-aligned (i.e. page-align up) */ +#ifndef PAGE_ALIGN +#define PAGE_ALIGN(addr) (((addr)+_page_size-1)&(~(_page_size-1))) +#endif +/* previous page-aligned (i.e. page-align down) */ +#ifndef PAGE_ALIGN_DOWN +#define PAGE_ALIGN_DOWN(addr) (((addr)+_page_size-1)&(~(_page_size-1))) +#endif + +#ifdef HAVE_MMAP +/* vector of last madvise hint */ +typedef struct _madvise_vec_t { + void *start; + ssize_t length; +} _madvise_vec_t; +_madvise_vec_t _madv_vec = { NULL, 0 }; +#endif + +#if defined CHECK_MADVISE_OVERLAPS +#define _madvise(_start, _off, _hint) \ + if ((_start) != _madv_vec.start && (ssize_t)(_off) != _madv_vec.length) { \ + _madv_vec.start = (_start) ; _madv_vec.length = (_off); \ + madvise((_start), (_off), (_hint)); \ + } +#else +#define _madvise(_start, _off, _hint) \ + madvise((_start), (_off), (_hint)) +#endif + +/* Open a database file, return its header and an open filehandle, + * positioned to the first cdp in the first rra. + * In the error path of rrd_open, only rrd_free(&rrd) has to be called + * before returning an error. Do not call rrd_close upon failure of rrd_open. + */ rrd_file_t *rrd_open( const char *const file_name, @@ -92,19 +136,25 @@ rrd_file_t *rrd_open( int version; #ifdef HAVE_MMAP + ssize_t _page_size = sysconf(_SC_PAGESIZE); int mm_prot = PROT_READ, mm_flags = 0; char *data; #endif off_t offset = 0; struct stat statb; - rrd_file_t *rrd_file = malloc(sizeof(rrd_file_t)); + rrd_file_t *rrd_file = NULL; + off_t newfile_size = 0; + if (rdwr & RRD_CREAT) + newfile_size = (off_t) rrd->stat_head; + rrd_init(rrd); + rrd_file = malloc(sizeof(rrd_file_t)); if (rrd_file == NULL) { rrd_set_error("allocating rrd_file descriptor for '%s'", file_name); return NULL; } memset(rrd_file, 0, sizeof(rrd_file_t)); - rrd_init(rrd); + #ifdef DEBUG if ((rdwr & (RRD_READONLY | RRD_READWRITE)) == (RRD_READONLY | RRD_READWRITE)) { @@ -118,9 +168,8 @@ rrd_file_t *rrd_open( #ifdef HAVE_MMAP mm_flags = MAP_PRIVATE; # ifdef MAP_NORESERVE - mm_flags |= MAP_NORESERVE; + mm_flags |= MAP_NORESERVE; /* readonly, so no swap backing needed */ # endif - mm_flags |= MAP_PRIVATE; #endif } else { if (rdwr & RRD_READWRITE) { @@ -137,33 +186,40 @@ rrd_file_t *rrd_open( } if (rdwr & RRD_READAHEAD) { #ifdef MAP_POPULATE - mm_flags |= MAP_POPULATE; + mm_flags |= MAP_POPULATE; /* populate ptes and data */ #endif -#if defined MAP_NONBLOCK && !defined USE_DIRECT_IO - mm_flags |= MAP_NONBLOCK; /* just populage ptes */ +#if defined MAP_NONBLOCK +// if (!(rdwr & RRD_COPY)) + mm_flags |= MAP_NONBLOCK; /* just populate ptes */ #endif - } else { #ifdef USE_DIRECT_IO + } else { flags |= O_DIRECT; #endif -#if 0 //def O_NONBLOCK - flags |= O_NONBLOCK; -#endif } +#ifdef O_NONBLOCK + flags |= O_NONBLOCK; +#endif if ((rrd_file->fd = open(file_name, flags, mode)) < 0) { rrd_set_error("opening '%s': %s", file_name, rrd_strerror(errno)); - return NULL; + goto out_free; } /* Better try to avoid seeks as much as possible. stat may be heavy but * many concurrent seeks are even worse. */ - if ((fstat(rrd_file->fd, &statb)) < 0) { + if (newfile_size == 0 && ((fstat(rrd_file->fd, &statb)) < 0)) { rrd_set_error("fstat '%s': %s", file_name, rrd_strerror(errno)); goto out_close; } - rrd_file->file_len = statb.st_size; - + if (newfile_size == 0) { + rrd_file->file_len = statb.st_size; + } else { + rrd_file->file_len = newfile_size; + lseek(rrd_file->fd, newfile_size - 1, SEEK_SET); + write(rrd_file->fd, "\0", 1); /* poke */ + lseek(rrd_file->fd, 0, SEEK_SET); + } #ifdef HAVE_POSIX_FADVISE /* In general we need no read-ahead when dealing with rrd_files. When we stop reading, it is highly unlikely that we start up again. @@ -191,26 +247,37 @@ rrd_file_t *rrd_open( /* lets see if the first read worked */ if (data == MAP_FAILED) { - rrd_set_error("error mmaping file '%s': %s", file_name, + rrd_set_error("mmaping file '%s': %s", file_name, rrd_strerror(errno)); goto out_close; } rrd_file->file_start = data; -#else -#endif -#ifdef USE_MADVISE - if (rdwr & RRD_COPY) { /*XXX: currently not used! */ - /* We will read everything in a moment (copying) */ - madvise(data, rrd_file->file_len, MADV_WILLNEED | MADV_SEQUENTIAL); + if (rdwr & RRD_CREAT) { + memset(data, DNAN, newfile_size - 1); goto out_done; } - /* We do not need to read anything in for the moment */ - madvise(data, rrd_file->file_len, MADV_DONTNEED); #endif - #ifdef USE_MADVISE - /* the stat_head will be needed soonish, so hint accordingly */ - madvise(data + offset, sizeof(stat_head_t), MADV_WILLNEED); + if (rdwr & RRD_COPY) { + /* We will read everything in a moment (copying) */ + _madvise(data, rrd_file->file_len, MADV_WILLNEED | MADV_SEQUENTIAL); + } else { +# ifndef ONE_PAGE + /* We do not need to read anything in for the moment */ + _madvise(data, rrd_file->file_len, MADV_DONTNEED); + /* the stat_head will be needed soonish, so hint accordingly */ + _madvise(data + PAGE_ALIGN_DOWN(offset), + PAGE_ALIGN(sizeof(stat_head_t)), + MADV_WILLNEED | MADV_RANDOM); + +# else +/* alternatively: keep 1 page worth of data, likely headers, + * don't need the rest. */ + _madvise(data, _page_size, MADV_WILLNEED | MADV_SEQUENTIAL); + _madvise(data + _page_size, (rrd_file->file_len >= _page_size) + ? rrd_file->file_len - _page_size : 0, MADV_DONTNEED); +# endif + } #endif __rrd_read(rrd->stat_head, stat_head_t, @@ -223,7 +290,7 @@ rrd_file_t *rrd_open( } if (rrd->stat_head->float_cookie != FLOAT_COOKIE) { - rrd_set_error("This RRD was created on other architecture"); + rrd_set_error("This RRD was created on another architecture"); goto out_nullify_head; } @@ -234,18 +301,20 @@ rrd_file_t *rrd_open( rrd->stat_head->version); goto out_nullify_head; } -#ifdef USE_MADVISE +#if defined USE_MADVISE && !defined ONE_PAGE /* the ds_def will be needed soonish, so hint accordingly */ - madvise(data + offset, sizeof(ds_def_t) * rrd->stat_head->ds_cnt, - MADV_WILLNEED); + _madvise(data + PAGE_ALIGN_DOWN(offset), + PAGE_ALIGN(sizeof(ds_def_t) * rrd->stat_head->ds_cnt), + MADV_WILLNEED); #endif __rrd_read(rrd->ds_def, ds_def_t, rrd->stat_head->ds_cnt); -#ifdef USE_MADVISE +#if defined USE_MADVISE && !defined ONE_PAGE /* the rra_def will be needed soonish, so hint accordingly */ - madvise(data + offset, sizeof(rra_def_t) * rrd->stat_head->rra_cnt, - MADV_WILLNEED); + _madvise(data + PAGE_ALIGN_DOWN(offset), + PAGE_ALIGN(sizeof(rra_def_t) * rrd->stat_head->rra_cnt), + MADV_WILLNEED); #endif __rrd_read(rrd->rra_def, rra_def_t, rrd->stat_head->rra_cnt); @@ -265,9 +334,10 @@ rrd_file_t *rrd_open( #endif rrd->live_head->last_up_usec = 0; } else { -#ifdef USE_MADVISE +#if defined USE_MADVISE && !defined ONE_PAGE /* the live_head will be needed soonish, so hint accordingly */ - madvise(data + offset, sizeof(live_head_t), MADV_WILLNEED); + _madvise(data + PAGE_ALIGN_DOWN(offset), + PAGE_ALIGN(sizeof(live_head_t)), MADV_WILLNEED); #endif __rrd_read(rrd->live_head, live_head_t, 1); @@ -284,37 +354,96 @@ rrd_file_t *rrd_open( __rrd_read(rrd->rra_ptr, rra_ptr_t, rrd->stat_head->rra_cnt); + rrd_file->header_len = offset; + rrd_file->pos = offset; #ifdef USE_MADVISE out_done: #endif - rrd_file->header_len = offset; - rrd_file->pos = offset; -/* we could close(rrd_file->fd); here, the mapping is still valid anyway */ return (rrd_file); out_nullify_head: rrd->stat_head = NULL; out_close: close(rrd_file->fd); + out_free: + free(rrd_file); return NULL; } + /* Close a reference to an rrd_file. */ + int rrd_close( rrd_file_t *rrd_file) { - int ret = 0; + int ret; + +#if defined HAVE_MMAP || defined DEBUG + ssize_t _page_size = sysconf(_SC_PAGESIZE); +#endif +#if defined DEBUG && DEBUG > 1 + /* pretty print blocks in core */ + off_t off; + unsigned char *vec; + + off = rrd_file->file_len + + ((rrd_file->file_len + _page_size - 1) / _page_size); + vec = malloc(off); + if (vec != NULL) { + memset(vec, 0, off); + if (mincore(rrd_file->file_start, rrd_file->file_len, vec) == 0) { + int prev; + unsigned is_in = 0, was_in = 0; + + for (off = 0, prev = 0; off < rrd_file->file_len; ++off) { + is_in = vec[off] & 1; /* if lsb set then is core resident */ + if (off == 0) + was_in = is_in; + if (was_in != is_in) { + fprintf(stderr, "%sin core: %p len %ld\n", + was_in ? "" : "not ", vec + prev, off - prev); + was_in = is_in; + prev = off; + } + } + fprintf(stderr, + "%sin core: %p len %ld\n", + was_in ? "" : "not ", vec + prev, off - prev); + } else + fprintf(stderr, "mincore: %s", rrd_strerror(errno)); + } +#endif /* DEBUG */ +#ifdef USE_MADVISE +# ifdef ONE_PAGE + /* Keep headers around, round up to next page boundary. */ + ret = + PAGE_ALIGN(rrd_file->header_len % _page_size + rrd_file->header_len); + if (rrd_file->file_len > ret) + _madvise(rrd_file->file_start + ret, + rrd_file->file_len - ret, MADV_DONTNEED); +# else + /* ignoring errors from RRDs that are smaller then the file_len+rounding */ + _madvise(rrd_file->file_start + PAGE_ALIGN_DOWN(rrd_file->header_len), + rrd_file->file_len - PAGE_ALIGN(rrd_file->header_len), + MADV_DONTNEED); +# endif +#endif #ifdef HAVE_MMAP ret = munmap(rrd_file->file_start, rrd_file->file_len); -// if (ret != 0) -// rrd_set_error("munmap rrd_file"); + if (ret != 0) + rrd_set_error("munmap rrd_file: %s", rrd_strerror(errno)); #endif + ret = close(rrd_file->fd); + if (ret != 0) + rrd_set_error("closing file: %s", rrd_strerror(errno)); free(rrd_file); rrd_file = NULL; return ret; } + /* Set position of rrd_file. */ + off_t rrd_seek( rrd_file_t *rrd_file, off_t off, @@ -339,59 +468,72 @@ off_t rrd_seek( return ret == -1; //XXX: or just ret to mimic lseek } + /* Get current position in rrd_file. */ + inline off_t rrd_tell( rrd_file_t *rrd_file) { return rrd_file->pos; } + /* read count bytes into buffer buf, starting at rrd_file->pos. - * Returns the number of bytes read. */ -ssize_t rrd_read( + * Returns the number of bytes read or <0 on error. */ + +inline ssize_t rrd_read( rrd_file_t *rrd_file, void *buf, size_t count) { #ifdef HAVE_MMAP - char *pos = rrd_file->file_start + rrd_file->pos; + size_t _cnt = count; + ssize_t _surplus = rrd_file->pos + _cnt - rrd_file->file_len; + if (_surplus > 0) { /* short read */ + _cnt -= _surplus; + } + if (_cnt == 0) + return 0; /* EOF */ + buf = memcpy(buf, rrd_file->file_start + rrd_file->pos, _cnt); - buf = memmove(buf, pos, count); - rrd_file->pos += count; /* mimmic read() semantics */ - return count; + rrd_file->pos += _cnt; /* mimmic read() semantics */ + return _cnt; #else ssize_t ret; ret = read(rrd_file->fd, buf, count); - //XXX: eventually add generic rrd_set_error(""); here - rrd_file->pos += count; /* mimmic read() semantics */ + if (ret > 0) + rrd_file->pos += ret; /* mimmic read() semantics */ return ret; #endif } + /* write count bytes from buffer buf to the current position * rrd_file->pos of rrd_file->fd. * Returns the number of bytes written. */ -ssize_t rrd_write( + +inline ssize_t rrd_write( rrd_file_t *rrd_file, const void *buf, size_t count) { - ssize_t ret = count; - #ifdef HAVE_MMAP - char *off, *new_pos; - - off = rrd_file->file_start + rrd_file->pos; - new_pos = memmove(rrd_file->file_start + rrd_file->pos, buf, count); - ret = new_pos - off; + memcpy(rrd_file->file_start + rrd_file->pos, buf, count); + rrd_file->pos += count; + return count; /* mimmic write() semantics */ #else - ret = write(rrd_file->fd, buf, count); + ssize_t _sz = write(rrd_file->fd, buf, count); + + if (_sz > 0) + rrd_file->pos += _sz; + return _sz; #endif - return ret; } + /* flush all data pending to be written to FD. */ + inline void rrd_flush( rrd_file_t *rrd_file) { @@ -401,6 +543,9 @@ inline void rrd_flush( } } + +/* Initialize RRD header. */ + void rrd_init( rrd_t *rrd) { @@ -414,10 +559,18 @@ void rrd_init( rrd->rrd_value = NULL; } -void rrd_free( + +/* free RRD header data. */ + +#ifdef HAVE_MMAP +inline void rrd_free( rrd_t UNUSED(*rrd)) { -#ifndef HAVE_MMAP +} +#else +void rrd_free( + rrd_t *rrd) +{ if (atoi(rrd->stat_head->version) < 3) free(rrd->live_head); free(rrd->stat_head); @@ -427,18 +580,24 @@ void rrd_free( free(rrd->pdp_prep); free(rrd->cdp_prep); free(rrd->rrd_value); -#endif } +#endif + /* routine used by external libraries to free memory allocated by * rrd library */ + void rrd_freemem( void *mem) { free(mem); } -int readfile( + +/* XXX: FIXME: missing documentation. */ +/*XXX: FIXME should be renamed to rrd_readfile or _rrd_readfile */ + +int /*_rrd_*/ readfile( const char *file_name, char **buffer, int skipfirst)