Coverage for scrapy/utils/memory : 60%

import os 

import sys 

import struct 

_vmvalue_scale = {'kB': 1024, 'mB': 1024*1024, 'KB': 1024, 'MB': 1024*1024} 

def get_vmvalue_from_procfs(vmkey='VmSize', pid=None): 

    """Return virtual memory value (in bytes) for the given pid using the /proc 

    filesystem. If pid is not given, it default to the current process pid. 

    Available keys are: VmSize, VmRSS (default), VmStk 

    """ 

14    if pid is None: 

        pid = os.getpid() 

    try: 

        t = open('/proc/%d/status' % pid) 

    except IOError: 

        raise RuntimeError("/proc filesystem not supported") 

19    if sys.platform == "sunos5": 

        return _vmvalue_solaris(vmkey, pid) 

    else: 

        v = t.read() 

        t.close() 

        # get vmkey line e.g. 'VmRSS:  9999  kB\n ...' 

        i = v.index(vmkey + ':') 

        v = v[i:].split(None, 3)  # whitespace 

27        if len(v) < 3: 

            return 0  # invalid format? 

        # convert Vm value to bytes 

        return int(v[1]) * _vmvalue_scale[v[2]] 

def procfs_supported(): 

    try: 

        open('/proc/%d/status' % os.getpid()) 

    except IOError: 

        return False 

    else: 

        return True 

def _vmvalue_solaris(vmkey, pid): 

     # Memory layout for struct psinfo. 

     # http://docs.sun.com/app/docs/doc/816-5174/proc-4?l=en&a=view 

    _psinfo_struct_format = ( 

        "10i"   # pr_flag [0] through pr_egid [9] 

        "5L"    # pr_addr [10] through pr_ttyydev [14] 

        "2H"    # pr_pctcpu [15] and pr_pctmem [16] 

        "6l"    # pr_start [17-18] through pr_ctime [21-22] 

        "16s"   # pr_fname [23] 

        "80s"   # pr_psargs [24] 

        "2i"    # pr_wstat[25] and pr_argc [26] 

        "2L"    # pr_argv [27] and pr_envp [28] 

        "b3x"   # pr_dmodel[29] and pr_pad2 

        "7i"    # pr_taskid [30] through pr_filler 

        "20i6l" # pr_lwp 

        ) 

    psinfo_file = os.path.join("/proc", str(pid), "psinfo") 

    with open(psinfo_file) as f: 

        parts = struct.unpack(_psinfo_struct_format, f.read()) 

    vmkey_index = { 

        'VmSize' : 11, # pr_size 

        'VmRSS'  : 12, # pr_rssize 

    } 

    vm_in_kB = parts[vmkey_index[vmkey]] 

    return vm_in_kB * 1024