/* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- */
// vim: ft=cpp:expandtab:ts=8:sw=4:softtabstop=4:
#ident "$Id$"
/*======
This file is part of PerconaFT.


Copyright (c) 2006, 2015, Percona and/or its affiliates. All rights reserved.

    PerconaFT is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License, version 2,
    as published by the Free Software Foundation.

    PerconaFT 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 PerconaFT.  If not, see <http://www.gnu.org/licenses/>.

----------------------------------------

    PerconaFT is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License, version 3,
    as published by the Free Software Foundation.

    PerconaFT 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 Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with PerconaFT.  If not, see <http://www.gnu.org/licenses/>.
======= */

#ident "Copyright (c) 2006, 2015, Percona and/or its affiliates. All rights reserved."

#include <portability/toku_config.h>

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <toku_assert.h>
#if defined(HAVE_MALLOC_H)
# include <malloc.h>
#elif defined(HAVE_SYS_MALLOC_H)
# include <sys/malloc.h>
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#if defined(HAVE_SYSCALL_H)
# include <syscall.h>
#endif
#if defined(HAVE_SYS_SYSCALL_H)
# include <sys/syscall.h>
#endif
#if defined(HAVE_SYS_SYSCTL_H)
# include <sys/sysctl.h>
#endif
#if defined(HAVE_PTHREAD_NP_H)
# include <pthread_np.h>
#endif
#include <inttypes.h>
#include <sys/time.h>
#if defined(HAVE_SYS_RESOURCE_H)
# include <sys/resource.h>
#endif
#include <sys/statvfs.h>
#include "toku_portability.h"
#include "toku_os.h"
#include "toku_time.h"
#include "memory.h"
#include <portability/toku_atomic.h>
#include <util/partitioned_counter.h>

int
toku_portability_init(void) {
    int r = toku_memory_startup();
    if (r == 0) {
        uint64_t hz;
        r = toku_os_get_processor_frequency(&hz); // get and cache freq
    }
    (void) toku_os_get_pagesize(); // get and cache pagesize
    return r;
}

void
toku_portability_destroy(void) {
    toku_memory_shutdown();
}

int
toku_os_getpid(void) {
    return getpid();
}

int
toku_os_gettid(void) {
#if defined(__NR_gettid)
    return syscall(__NR_gettid);
#elif defined(SYS_gettid)
    return syscall(SYS_gettid);
#elif defined(HAVE_PTHREAD_GETTHREADID_NP)
    return pthread_getthreadid_np();
#else
# error "no implementation of gettid available"
#endif
}

int
toku_os_get_number_processors(void) {
    return sysconf(_SC_NPROCESSORS_CONF);
}

int
toku_os_get_number_active_processors(void) {
    int n = sysconf(_SC_NPROCESSORS_ONLN);
#define DO_TOKU_NCPUS 1
#if DO_TOKU_NCPUS
    {
        char *toku_ncpus = getenv("TOKU_NCPUS");
        if (toku_ncpus) {
            int ncpus = atoi(toku_ncpus);
            if (ncpus < n)
                n = ncpus;
        }
    }
#endif
    return n;
}

int toku_cached_pagesize = 0;

int
toku_os_get_pagesize(void) {
    int pagesize = toku_cached_pagesize;
    if (pagesize == 0) {
        pagesize = sysconf(_SC_PAGESIZE);
        if (pagesize) {
            toku_cached_pagesize = pagesize;
        }
    }
    return pagesize;
}

uint64_t
toku_os_get_phys_memory_size(void) {
#if defined(_SC_PHYS_PAGES)
    uint64_t npages = sysconf(_SC_PHYS_PAGES);
    uint64_t pagesize = sysconf(_SC_PAGESIZE);
    return npages*pagesize;
#elif defined(HAVE_SYS_SYSCTL_H)
    uint64_t memsize;
    size_t len = sizeof memsize;
    sysctlbyname("hw.memsize", &memsize, &len, NULL, 0);
    return memsize;
#else
# error "cannot find _SC_PHYS_PAGES or sysctlbyname()"
#endif
}

int
toku_os_get_file_size(int fildes, int64_t *fsize) {
    toku_struct_stat sbuf;
    int r = fstat(fildes, &sbuf);
    if (r==0) {
        *fsize = sbuf.st_size;
    }
    return r;
}

int
toku_os_get_unique_file_id(int fildes, struct fileid *id) {
    toku_struct_stat statbuf;
    memset(id, 0, sizeof(*id));
    int r=fstat(fildes, &statbuf);
    if (r==0) {
        id->st_dev = statbuf.st_dev;
        id->st_ino = statbuf.st_ino;
    }
    return r;
}

int
toku_os_lock_file(const char *name) {
    int r;
    int fd = open(name, O_RDWR|O_CREAT, S_IRUSR | S_IWUSR);
    if (fd>=0) {
        r = flock(fd, LOCK_EX | LOCK_NB);
        if (r!=0) {
            r = errno; //Save errno from flock.
            close(fd);
            fd = -1; //Disable fd.
            errno = r;
        }
    }
    return fd;
}

int
toku_os_unlock_file(int fildes) {
    int r = flock(fildes, LOCK_UN);
    if (r==0) r = close(fildes);
    return r;
}

int
toku_os_mkdir(const char *pathname, mode_t mode) {
    int r = mkdir(pathname, mode);
    return r;
}

int
toku_os_get_process_times(struct timeval *usertime, struct timeval *kerneltime) {
    int r;
    struct rusage rusage;
    r = getrusage(RUSAGE_SELF, &rusage);
    if (r == -1)
        return get_error_errno();
    if (usertime) 
        *usertime = rusage.ru_utime;
    if (kerneltime)
        *kerneltime = rusage.ru_stime;
    return 0;
}

int
toku_os_initialize_settings(int UU(verbosity)) {
    int r = 0;
    static int initialized = 0;
    assert(initialized==0);
    initialized=1;
    return r;
}

bool toku_os_is_absolute_name(const char* path) {
    return path[0] == '/';
}

int
toku_os_get_max_process_data_size(uint64_t *maxdata) {
    int r;
    struct rlimit rlimit;

    r = getrlimit(RLIMIT_DATA, &rlimit);
    if (r == 0) {
        uint64_t d;
        d = rlimit.rlim_max;
	// with the "right" macros defined, the rlimit is a 64 bit number on a
	// 32 bit system.  getrlimit returns 2**64-1 which is clearly wrong.

        // for 32 bit processes, we assume that 1/2 of the address space is
        // used for mapping the kernel.  this may be pessimistic.
        if (sizeof (void *) == 4 && d > (1ULL << 31))
            d = 1ULL << 31;
	*maxdata = d;
    } else
        r = get_error_errno();
    return r;
}

int
toku_stat(const char *name, toku_struct_stat *buf) {
    int r = stat(name, buf);
    return r;
}

int
toku_fstat(int fd, toku_struct_stat *buf) {
    int r = fstat(fd, buf);
    return r;
}

static int
toku_get_processor_frequency_sys(uint64_t *hzret) {
    int r;
    FILE *fp = fopen("/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq", "r");
    if (!fp) 
        r = get_error_errno();
    else {
        unsigned int khz = 0;
        if (fscanf(fp, "%u", &khz) == 1) {
            *hzret = khz * 1000ULL;
            r = 0;
        } else
            r = ENOENT;
        fclose(fp);
    }
    return r;
}

static int
toku_get_processor_frequency_cpuinfo(uint64_t *hzret) {
    int r;
    FILE *fp = fopen("/proc/cpuinfo", "r");
    if (!fp) {
        r = get_error_errno();
    } else {
        uint64_t maxhz = 0;
        /*
          Some lines in the "/proc/cpuinfo" output can be long, e.g.:
            "flags  : fpu vme de pse tsc ms .... smep erms"
          In case a line does not fit into "buf", it will be read
          in parts by multiple "fgets" calls. This is ok, as
          it is very unlikely that a non-leading substring of a line
          will match again the pattern "processor: %u".
        */
        char buf[512];
        while (fgets(buf, (int) sizeof(buf), fp) != NULL) {
            unsigned int cpu;
            sscanf(buf, "processor : %u", &cpu);
            unsigned int ma, mb;
            if (sscanf(buf, "cpu MHz : %u.%u", &ma, &mb) == 2) {
                uint64_t hz = ma * 1000000ULL + mb * 1000ULL;
                if (hz > maxhz)
                    maxhz = hz;
            }
        }
        fclose(fp);
        *hzret = maxhz;
        r = maxhz == 0 ? ENOENT : 0;;
    }
    return r;
}

static int
toku_get_processor_frequency_sysctl(const char * const cmd, uint64_t *hzret) {
    int r = 0;
    FILE *fp = popen(cmd, "r");
    if (!fp) {
        r = EINVAL;  // popen doesn't return anything useful in errno,
                     // gotta pick something
    } else {
        r = fscanf(fp, "%" SCNu64, hzret);
        if (r != 1) {
            r = get_maybe_error_errno();
        } else {
            r = 0;
        }
        pclose(fp);
    }
    return r;
}

static uint64_t toku_cached_hz; // cache the value of hz so that we avoid opening files to compute it later

int 
toku_os_get_processor_frequency(uint64_t *hzret) {
    int r;
    if (toku_cached_hz) {
        *hzret = toku_cached_hz;
        r = 0;
    } else {
        r = toku_get_processor_frequency_sys(hzret);
        if (r != 0)
            r = toku_get_processor_frequency_cpuinfo(hzret);
        if (r != 0)
            r = toku_get_processor_frequency_sysctl("sysctl -n hw.cpufrequency", hzret);
        if (r != 0)
            r = toku_get_processor_frequency_sysctl("sysctl -n machdep.tsc_freq", hzret);
        if (r == 0)
            toku_cached_hz = *hzret;
    }
    return r;
}

int
toku_get_filesystem_sizes(const char *path, uint64_t *avail_size, uint64_t *free_size, uint64_t *total_size) {
    struct statvfs s;
    int r = statvfs(path, &s);
    if (r == -1) {
        r = get_error_errno();
    } else {
        // get the block size in bytes
        uint64_t bsize = s.f_frsize ? s.f_frsize : s.f_bsize;
        // convert blocks to bytes
        if (avail_size)
            *avail_size = (uint64_t) s.f_bavail * bsize;
        if (free_size) 
            *free_size = (uint64_t) s.f_bfree * bsize;
        if (total_size) 
            *total_size = (uint64_t) s.f_blocks * bsize;
    }
    return r;
}


int
toku_dup2(int fd, int fd2) {
    int r;
    r = dup2(fd, fd2);
    return r;
}


// Time
static       double seconds_per_clock = -1;

double tokutime_to_seconds(tokutime_t t) {
    // Convert tokutime to seconds.
    if (seconds_per_clock<0) {
	uint64_t hz;
	int r = toku_os_get_processor_frequency(&hz);
	assert(r==0);
	// There's a race condition here, but it doesn't really matter.  If two threads call tokutime_to_seconds
	// for the first time at the same time, then both will fetch the value and set the same value.
	seconds_per_clock = 1.0/hz;
    }
    return t*seconds_per_clock;
}

#include <toku_race_tools.h>
void __attribute__((constructor)) toku_portability_helgrind_ignore(void);
void
toku_portability_helgrind_ignore(void) {
    TOKU_VALGRIND_HG_DISABLE_CHECKING(&toku_cached_hz, sizeof toku_cached_hz);
    TOKU_VALGRIND_HG_DISABLE_CHECKING(&toku_cached_pagesize, sizeof toku_cached_pagesize);
}