/*
 * gmem.c
 *
 * Memory routines with out-of-memory checking.
 *
 * Copyright 1996 Derek B. Noonburg
 */

#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include "gmem.h"

#ifdef DEBUG_MEM

typedef struct _GMemHdr {
  int size;
  int index;
  struct _GMemHdr *next;
} GMemHdr;

#define gMemHdrSize ((sizeof(GMemHdr) + 7) & ~7)
#define gMemTrlSize (sizeof(long))

#if gmemTrlSize==8
#define gMemDeadVal 0xdeadbeefdeadbeef
#else
#define gMemDeadVal 0xdeadbeef
#endif

/* round data size so trailer will be aligned */
#define gMemDataSize(size) \
  ((((size) + gMemTrlSize - 1) / gMemTrlSize) * gMemTrlSize)

#define gMemNLists    64
#define gMemListShift  4
#define gMemListMask  (gMemNLists - 1)
static GMemHdr *gMemList[gMemNLists] = {
  NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
  NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
  NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
  NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
  NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
  NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
  NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
  NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
};

static int gMemIndex = 0;
static int gMemAlloc = 0;

#endif /* DEBUG_MEM */

void *gmalloc(int size) {
#ifdef DEBUG_MEM
  int size1;
  char *mem;
  GMemHdr *hdr;
  void *data;
  int lst;
  long *trl, *p;

  if (size == 0)
    return NULL;
  size1 = gMemDataSize(size);
  if (!(mem = (char *)malloc(size1 + gMemHdrSize + gMemTrlSize))) {
    fprintf(stderr, "Out of memory\n");
    exit(1);
  }
  hdr = (GMemHdr *)mem;
  data = (void *)(mem + gMemHdrSize);
  trl = (long *)(mem + gMemHdrSize + size1);
  hdr->size = size;
  hdr->index = gMemIndex++;
  lst = ((int)hdr >> gMemListShift) & gMemListMask;
  hdr->next = gMemList[lst];
  gMemList[lst] = hdr;
  ++gMemAlloc;
  for (p = (long *)data; p <= trl; ++p)
    *p = gMemDeadVal;
  return data;
#else
  void *p;

  if (size == 0)
    return NULL;
  if (!(p = malloc(size))) {
    fprintf(stderr, "Out of memory\n");
    exit(1);
  }
  return p;
#endif
}

void *grealloc(void *p, int size) {
#ifdef DEBUG_MEM
  GMemHdr *hdr;
  void *q;
  int oldSize;

  if (size == 0) {
    if (p)
      gfree(p);
    return NULL;
  }
  if (p) {
    hdr = (GMemHdr *)((char *)p - gMemHdrSize);
    oldSize = hdr->size;
    q = gmalloc(size);
    memcpy(q, p, size < oldSize ? size : oldSize);
    gfree(p);
  } else {
    q = gmalloc(size);
  }
  return q;
#else
  void *q;

  if (size == 0) {
    if (p)
      free(p);
    return NULL;
  }
  if (p)
    q = realloc(p, size);
  else
    q = malloc(size);
  if (!q) {
    fprintf(stderr, "Out of memory\n");
    exit(1);
  }
  return q;
#endif
}

void gfree(void *p) {
#ifdef DEBUG_MEM
  int size;
  GMemHdr *hdr;
  GMemHdr *prevHdr, *q;
  int lst;
  long *trl, *clr;

  if (p) {
    hdr = (GMemHdr *)((char *)p - gMemHdrSize);
    lst = ((int)hdr >> gMemListShift) & gMemListMask;
    for (prevHdr = NULL, q = gMemList[lst]; q; prevHdr = q, q = q->next) {
      if (q == hdr)
	break;
    }
    if (q) {
      if (prevHdr)
	prevHdr->next = hdr->next;
      else
	gMemList[lst] = hdr->next;
      --gMemAlloc;
      size = gMemDataSize(hdr->size);
      trl = (long *)((char *)hdr + gMemHdrSize + size);
      if (*trl != gMemDeadVal) {
	fprintf(stderr, "Overwrite past end of block %d at address %p\n",
		hdr->index, p);
      }
      for (clr = (long *)hdr; clr <= trl; ++clr)
	*clr = gMemDeadVal;
      free(hdr);
    } else {
      fprintf(stderr, "Attempted to free bad address %p\n", p);
    }
  }
#else
  if (p)
    free(p);
#endif
}

#ifdef DEBUG_MEM
void gMemReport(FILE *f) {
  GMemHdr *p;
  int lst;

  fprintf(f, "%d memory allocations in all\n", gMemIndex);
  if (gMemAlloc > 0) {
    fprintf(f, "%d memory blocks left allocated:\n", gMemAlloc);
    fprintf(f, " index     size\n");
    fprintf(f, "-------- --------\n");
    for (lst = 0; lst < gMemNLists; ++lst) {
      for (p = gMemList[lst]; p; p = p->next)
	fprintf(f, "%8d %8d\n", p->index, p->size);
    }
  } else {
    fprintf(f, "No memory blocks left allocated\n");
  }
}
#endif

char *copyString(char *s) {
  char *s1;

  s1 = (char *)gmalloc(strlen(s) + 1);
  strcpy(s1, s);
  return s1;
}
