/* IBM_PROLOG_BEGIN_TAG                                                   */
/* This is an automatically generated prolog.                             */
/*                                                                        */
/*                                                                        */
/*                                                                        */
/* Licensed Materials - Property of IBM                                   */
/*                                                                        */
/* (C) COPYRIGHT International Business Machines Corp. 2002,2006          */
/* All Rights Reserved                                                    */
/*                                                                        */
/* US Government Users Restricted Rights - Use, duplication or            */
/* disclosure restricted by GSA ADP Schedule Contract with IBM Corp.      */
/*                                                                        */
/* IBM_PROLOG_END_TAG                                                     */

/*====================================================================
 *
 * tsgetusage command: get a summary of each user's disk usage
 *
 * Syntax: tsgetusage [ options ] fsPath
 *
 *   fsPath: the directory where the root of the filesystem is found.
 *
 *==================================================================*/

#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <pwd.h>
#include <grp.h>
#include <sys/types.h>
#include <gpfs.h>


/* Define globals */
static int Verbose = 1;
static int GroupStats = 0;
static int DiskUsgFormat = 0;
static char* ProgNameP = NULL;

/* Define stat structure */
typedef struct uStat_struct
{
  struct uStat_struct *nextP;
  unsigned int         id;
  gpfs_off64_t         blockCount;
  gpfs_off64_t         inodeCount;
} uStat;

/* Define hash table for collecting stats */
static uStat **HashPP = NULL;
static int     HashSize = 1027;
#define HASH(_id) (_id % HashSize)


/* Print usage statement and exit. */
static void Usage()
{
  fprintf(stderr, "Usage: %s [-g][-h][-q][-v][-u][-H hashTableSize] fsPath\n"
            "\twhere:\tfsPath\tpath to file system\n"
            "\t\t-u\toutputs data in diskusg format for acctdisk\n"
            "\t\t-g\tcollect stats for groups\n"
            "\t\t-H\tsets the hash table size (default %d)\n"
            "\t\t-h\tprints this message\n"
            "\t\t-q\toutputs only the resulting stats\n"
            "\t\t-v\tprint information about each file\n",
          ProgNameP, HashSize);
  fflush(stderr);
  exit(1);
}

/* Initialize hash table for collecting statistics */
static int InitHash()
{
  int hashTableSize = HashSize * sizeof(uStat *);

  HashPP = (uStat **)malloc(hashTableSize);
  if (HashPP == NULL)
  {
    fprintf(stderr, "No space to allocate hash table (%d bytes)\n",
            hashTableSize);
    return ENOMEM;
  }

  memset(HashPP, '\0', hashTableSize);
  return 0;
}

/* Find and increment an user/group's stat entry.
   Create the entry, if it is not found. */
static int IncStats(unsigned int id,
                    gpfs_off64_t nBlocks, gpfs_off64_t nInodes)
{
  uStat *uP, *prevP;
  int hashVal;

  /* Locate stat entry in hash table */
  prevP = NULL;
  hashVal = HASH(id);
  for (uP = HashPP[ hashVal ]; uP != NULL; uP = uP->nextP)
  {
    if (uP->id == id)
    {
      /* Entry found. Update its counters */
      uP->blockCount += nBlocks;
      uP->inodeCount += nInodes;

      /* Move entry to head of hash list */
      if (prevP != NULL)
      {
        prevP->nextP = uP->nextP;
        uP->nextP = HashPP[ hashVal ];
        HashPP[ hashVal ] = uP;
      }
      return 0;
    }
    prevP = uP;
  }

  /* Entry not found. Create a new one. */
  uP = (uStat *)malloc(sizeof(*uP));
  if (uP == NULL)
  {
    fprintf(stderr, "No space to allocate stat entry (%d bytes)\n",
            sizeof(*uP));
    return ENOMEM;
  }

  /* Initialize new entry & insert at head of hash list */
  uP->id = id;
  uP->blockCount = nBlocks;
  uP->inodeCount = nInodes;
  uP->nextP = HashPP[ hashVal ];
  HashPP[ hashVal ] = uP;

  return 0;
}

/* Traverse has table and print each entry */
static int PrintStats(const char* fsPathP)
{
  int i;
  uStat *uP;
  char *nameP;
  struct group *grpP;
  struct passwd *usrP;

  if (Verbose > 0)
  {
    printf("%s statistics for file system %s:\n",
           (GroupStats != 0) ? "Group" : "User",
           fsPathP);
    printf("%10s %32s %12s %12s\n",
           (GroupStats != 0) ? "gid" : "uid",
           "name", "KB", "inodes");
  }

  /* Traverse the hash table */
  for (i = 0; i < HashSize; i++)
  {
    /* Traverse each hash list */
    for (uP = HashPP[i]; uP != NULL; uP = uP->nextP)
    {
      /* Convert ids into readable names */
      if (GroupStats != 0)
      {
        grpP = getgrgid((gid_t) uP->id);
        if (grpP == NULL)
          nameP = "n/a";
        else
          nameP = grpP->gr_name;
      }
      else
      {
        usrP = getpwuid((uid_t) uP->id);
        if (usrP == NULL)
          nameP = "n/a";
        else
          nameP = usrP->pw_name;
      }

      /* Print stats on stdout */
      if (DiskUsgFormat)
        printf("%u\t%s\t%lld\n",
               uP->id, nameP, (uP->blockCount+1)/2);
      else
        printf("%10u %32s %12lld %12lld\n",
               uP->id, nameP, (uP->blockCount+1)/2, uP->inodeCount);
    }
  }
  if (Verbose > 0)
    printf("%s statistics for file system %s complete.\n",
           (GroupStats != 0) ? "Group" : "User",
           fsPathP);

  return 0;
}

/* Scan the file system to collect the requested stats */
int scanFileSystem(const char *fsPathP)
{
  int rc = 0;
  gpfs_iscan_t *iscanP = NULL;
  gpfs_fssnap_handle_t *fsP = NULL;
  const gpfs_iattr_t *iattrP;
  gpfs_ino_t lastInodeNum = 0;
  gpfs_ino_t maxInodeNum;
  char modeBuf[32];

  if (Verbose > 1)
    fprintf(stderr, "Scanning %s...\n", fsPathP);
  else if (Verbose > 0)
    printf("Scanning %s...\n", fsPathP);

  /* Open inode scan */
  fsP = gpfs_get_fssnaphandle_by_path(fsPathP);
  if (fsP == NULL)
  {
    rc = errno;
    fprintf(stderr, "%s: gpfs_get_fssnaphandle_by_path(%s): %s\n",
            ProgNameP, fsPathP, strerror(rc));
    goto done;
  }

  iscanP = gpfs_open_inodescan(fsP, NULL, &maxInodeNum);
  if (iscanP == NULL)
  {
    rc = errno;
    fprintf(stderr, "%s: gpfs_open_inodescan(%s): %s\n",
            ProgNameP, fsPathP, strerror(rc));
    goto done;
  }

  /* Loop over inodes in the file system */
  while (1)
  {
    rc = gpfs_next_inode(iscanP, maxInodeNum, &iattrP);
    if (rc != 0)
    {
      rc = errno;
      fprintf(stderr, "%s: gpfs_next_inode(%s,%d): %s\n",
              ProgNameP, fsPathP, lastInodeNum, strerror(rc));
      goto done;
    }

    /* A null ptr indicates end of scan */
    if (iattrP == NULL)
      break;

    /* Save inode number */
    lastInodeNum = iattrP->ia_inode;

    /* Skip over deleted files. */
    if (iattrP->ia_nlink == 0)
      continue;

    if (Verbose > 1)
      fprintf(stderr,
              "inode %9d uid %6d gid %6d bytes %10lld blks %10lld\n",
              iattrP->ia_inode, iattrP->ia_uid, iattrP->ia_gid,
              iattrP->ia_size, iattrP->ia_blocks);

    if (GroupStats != 0)
      rc = IncStats((unsigned int) iattrP->ia_gid,
                    iattrP->ia_blocks, 1);
    else
      rc = IncStats((unsigned int) iattrP->ia_uid,
                    iattrP->ia_blocks, 1);
    if (rc != 0)
      goto done;
  }

done:
  if (iscanP != NULL)
    gpfs_close_inodescan(iscanP);
  if (fsP != NULL)
    gpfs_free_fssnaphandle(fsP);

  if (Verbose > 1)
    if (rc != 0)
      fprintf(stderr, "Scan %s complete: %s\n", fsPathP, strerror(rc));
    else
      fprintf(stderr, "Scan %s complete\n", fsPathP);

  return rc;
}

/* main */
int main(int argc, char *argv[])
{
  int i, rc;
  const char* fsPathP;

  /* Save program name for usage statement */
  ProgNameP = argv[0];
  fsPathP = NULL;

  /* parse options */
  for (i = 1; i < argc; i++)
  {
    if (strcmp(argv[i], "-v") == 0)
      Verbose = 2;
    else if (strcmp(argv[i], "-q") == 0)
      Verbose = 0;
    else if (strcmp(argv[i], "-u") == 0)
    {
      DiskUsgFormat = 1;
      Verbose = 0;
    }
    else if (strcmp(argv[i], "-g") == 0)
      GroupStats = 1;
    else if (strcmp(argv[i], "-H") == 0)
    {
      i++;
      if (i < argc)
      {
        HashSize = atoi(argv[i]);
        if (HashSize <= 0)
        {
          fprintf(stderr, "%s: Invalid value for -H (%d)\n",
                  ProgNameP, HashSize);
          exit(2);
        }
      }
      else
      {
        fprintf(stderr, "%s: Missing arg for -H\n", ProgNameP);
        Usage();
      }
    }
    else if ((strcmp(argv[i], "-h") == 0) ||
             (strcmp(argv[i], "-?") == 0))
      Usage();
    else if (fsPathP == NULL)
      fsPathP = argv[i];
    else
    {
      fprintf(stderr, "%s: Unknown arg \"%s\"\n", ProgNameP, argv[i]);
      Usage();
    }
  }

  if (fsPathP == NULL)
  {
    fprintf(stderr, "%s: Missing fsPath arg\n", ProgNameP);
    Usage();
  }

  /* Initialize hash tables */
  rc = InitHash();
  if (rc != 0)
    goto done;

  /* Scan the file system to collect the requested stats */
  rc = scanFileSystem(fsPathP);
  if (rc != 0)
    goto done;

  /* Display results */
  rc = PrintStats(fsPathP);

done:
  return rc;
}