// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// This file contains internal routines that are called by other files in
// base/process/.

#ifndef BASE_PROCESS_INTERNAL_AIX_H_
#define BASE_PROCESS_INTERNAL_AIX_H_

#include <stddef.h>
#include <stdint.h>
#include <unistd.h>
#include <string>
#include <vector>

#include "base/files/file_path.h"

namespace base {

namespace internalAIX {

// "/proc"
extern const char kProcDir[];

// "psinfo"
extern const char kStatFile[];

// Returns a FilePath to "/proc/pid".
base::FilePath GetProcPidDir(pid_t pid);

// Take a /proc directory entry named |d_name|, and if it is the directory for
// a process, convert it to a pid_t.
// Returns 0 on failure.
// e.g. /proc/self/ will return 0, whereas /proc/1234 will return 1234.
pid_t ProcDirSlotToPid(const char* d_name);

// Reads /proc/<pid>/stat into |buffer|. Returns true if the file can be read
// and is non-empty.
bool ReadProcStats(pid_t pid, std::string* buffer);

// Takes |stats_data| and populates |proc_stats| with the values split by
// spaces. Taking into account the 2nd field may, in itself, contain spaces.
// Returns true if successful.
bool ParseProcStats(const std::string& stats_data,
                    std::vector<std::string>* proc_stats);

// Fields from /proc/<pid>/psinfo.
// If the ordering ever changes, carefully review functions that use these
// values.
// For AIX this is the bare minimum that we need. Most of the commented out
// fields can still be extracted but currently none of these are required.
enum ProcStatsFields {
  VM_COMM = 1,  // Filename of executable, without parentheses.
  //  VM_STATE          = 2,   // Letter indicating the state of the process.
  VM_PPID = 3,  // PID of the parent.
  VM_PGRP = 4,  // Process group id.
  //  VM_UTIME          = 13,  // Time scheduled in user mode in clock ticks.
  //  VM_STIME          = 14,  // Time scheduled in kernel mode in clock ticks.
  //  VM_NUMTHREADS     = 19,  // Number of threads.
  //  VM_STARTTIME      = 21,  // The time the process started in clock ticks.
  //  VM_VSIZE          = 22,  // Virtual memory size in bytes.
  //  VM_RSS            = 23,  // Resident Set Size in pages.
};

// Reads the |field_num|th field from |proc_stats|. Returns 0 on failure.
// This version does not handle the first 3 values, since the first value is
// simply |pid|, and the next two values are strings.
int64_t GetProcStatsFieldAsInt64(const std::vector<std::string>& proc_stats,
                                 ProcStatsFields field_num);

// Same as GetProcStatsFieldAsInt64(), but for size_t values.
size_t GetProcStatsFieldAsSizeT(const std::vector<std::string>& proc_stats,
                                ProcStatsFields field_num);

// Convenience wrapper around GetProcStatsFieldAsInt64(), ParseProcStats() and
// ReadProcStats(). See GetProcStatsFieldAsInt64() for details.
int64_t ReadProcStatsAndGetFieldAsInt64(pid_t pid, ProcStatsFields field_num);

// Same as ReadProcStatsAndGetFieldAsInt64() but for size_t values.
size_t ReadProcStatsAndGetFieldAsSizeT(pid_t pid, ProcStatsFields field_num);

}  // namespace internalAIX
}  // namespace base

#endif  // BASE_PROCESS_INTERNAL_AIX_H_
