Add pds

1 files changed, 417 insertions, 0 deletions

diff --git a/src/pds.h b/src/pds.h
new file mode 100644
index 0000000..e0b9df2
--- /dev/null
+++ b/src/pds.h
@@ -0,0 +1,417 @@
+#ifndef _PDS_H
+#define _PDS_H
+
+/* pointer data structures */
+/* Simple stack with psuh/pop */
+/* Simple hashmap with char * as key */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#ifndef PDSDEF
+#ifdef PDS_STATIC
+#define PDSDEF static
+#else
+#define PDSDEF extern
+#endif
+#endif
+
+#define PSTACK_RESIZE_FACTOR 2
+#define PSTACK_INIT_CAPACITY 16
+
+  typedef struct pstack
+  {
+    uint64_t cap;
+    uint64_t size;
+    uint64_t stride;
+    void*    data;
+  } pstack;
+
+  /* Exported API */
+  /* Stack */
+  PDSDEF void* _pstack_create(uint64_t length, uint64_t stride);
+#ifndef pstack_create
+#define pstack_create(type) _pstack_create(PSTACK_INIT_CAPACITY, sizeof(type));
+#endif
+
+#ifndef pstack_create_ex
+#define pstack_create_ex(type, cap) _pstack_create(cap, sizeof(type));
+#endif
+
+  PDSDEF void* _pstack_push(void* list, const void* value_ptr);
+#ifndef pstack_push
+#define pstack_push(list, val)                                                 \
+  do {                                                                         \
+    typeof(val) tmp = val;                                                     \
+    list            = _pstack_push(list, &tmp);                                \
+  } while (0);
+#endif
+
+  PDSDEF uint64_t pstack_capacity(void* list);
+  PDSDEF uint64_t pstack_size(void* list);
+  PDSDEF uint64_t pstack_stride(void* list);
+  PDSDEF void     pstack_length_set(void* list, uint64_t value);
+  PDSDEF void     pstack_destroy(void* list);
+  PDSDEF void*    pstack_resize(void* list);
+
+  /* Hashmap */
+
+  typedef struct phash
+  {
+    uint64_t element_size;
+    uint32_t element_count;
+    int8_t   is_pointer_type;
+    void*    memory;
+  } phash;
+
+  /* Exported API */
+
+  PDSDEF void   phash_create(uint64_t element_size,
+                             uint32_t element_count,
+                             void*    memory,
+                             int8_t   is_pointer_type,
+                             phash*   out_phash);
+  PDSDEF void   phash_destroy(phash* table);
+  PDSDEF int8_t phash_set(phash* table, const char* name, void* value);
+  PDSDEF int8_t phash_set_ptr(phash* table, const char* name, void** value);
+  PDSDEF int8_t phash_get(phash* table, const char* name, void* out_value);
+  PDSDEF int8_t phash_get_ptr(phash* table, const char* name, void** out_value);
+
+#ifdef __cplusplus
+}
+#endif
+
+/* End header file */
+#endif /* _PDS_H */
+
+#ifdef PDS_IMPLEMENTATION
+
+PDSDEF void*
+_pstack_create(uint64_t length, uint64_t stride)
+{
+  uint64_t header_size = sizeof(pstack);
+  uint64_t list_size   = length * stride;
+
+  pstack* list = (pstack*)malloc(header_size + list_size);
+  list->cap    = length;
+  list->size   = 0;
+  list->stride = stride;
+  list->data   = NULL;
+
+  return (void*)((uint8_t*)list + header_size);
+}
+
+PDSDEF uint64_t
+pstack_capacity(void* list)
+{
+  uint64_t header_size = sizeof(pstack);
+  pstack*  header      = (pstack*)((uint8_t*)list - header_size);
+  return header->cap;
+}
+
+PDSDEF uint64_t
+pstack_size(void* list)
+{
+  uint64_t header_size = sizeof(pstack);
+  pstack*  header      = (pstack*)((uint8_t*)list - header_size);
+  return header->size;
+}
+
+PDSDEF uint64_t
+pstack_stride(void* list)
+{
+  uint64_t header_size = sizeof(pstack);
+  pstack*  header      = (pstack*)((uint8_t*)list - header_size);
+  return header->stride;
+}
+
+PDSDEF void
+pstack_length_set(void* list, uint64_t value)
+{
+  uint64_t header_size = sizeof(pstack);
+  pstack*  header      = (pstack*)((uint8_t*)list - header_size);
+  header->size         = value;
+}
+
+PDSDEF void
+pstack_destroy(void* list)
+{
+  if (list) {
+    uint64_t header_size = sizeof(pstack);
+    pstack*  header      = (pstack*)((uint8_t*)list - header_size);
+    free(header);
+  }
+}
+
+PDSDEF void*
+pstack_resize(void* list)
+{
+  uint64_t header_size = sizeof(pstack);
+  pstack*  header      = (pstack*)((uint8_t*)list - header_size);
+  if (header->cap == 0) {
+    fprintf(stderr,
+            "pstack_resize called on an list with 0 capacity. This should not "
+            "be possible.\n");
+    return 0;
+  }
+  void* temp =
+    _pstack_create((PSTACK_RESIZE_FACTOR * header->cap), header->stride);
+
+  pstack* new_header = (pstack*)((uint8_t*)temp - header_size);
+  new_header->size   = header->size;
+
+  memcpy(temp, list, header->size * header->stride);
+
+  pstack_destroy(list);
+  return temp;
+}
+
+PDSDEF void*
+_pstack_push(void* list, const void* value_ptr)
+{
+  uint64_t header_size = sizeof(pstack);
+  pstack*  header      = (pstack*)((uint8_t*)list - header_size);
+  if (header->size >= header->cap) {
+    list = pstack_resize(list);
+  }
+  header = (pstack*)((uint8_t*)list - header_size);
+
+  uint64_t addr = (uint64_t)list;
+  addr += (header->size * header->stride);
+  memcpy((void*)addr, value_ptr, header->stride);
+  pstack_length_set(list, header->size + 1);
+  return list;
+}
+
+PDSDEF int
+pstack_pop(void* list, void* dest)
+{
+  uint64_t size   = pstack_size(list);
+  uint64_t stride = pstack_stride(list);
+  if (size < 1) {
+    // fprintf(stderr, "pstack_pop called on an empty pstack. Nothing to be
+    // done.\n");
+    return 1;
+  }
+  uint64_t addr = (uint64_t)list;
+  addr += ((size - 1) * stride);
+  memcpy(dest, (void*)addr, stride);
+  pstack_length_set(list, size - 1);
+  return 0;
+}
+
+/* int */
+/* main() */
+/* { */
+/*   int* lst = pstack_create(int); */
+/*   pstack_push(lst, 1); */
+/*   pstack_push(lst, 2); */
+
+/*   int i; */
+/*   while (!pstack_pop(lst, &i)) { */
+/*     printf("%d\n", i); */
+/*   } */
+
+/*   char** lst2 = pstack_create(char*); */
+/*   pstack_push(lst2, &"Hello"); */
+/*   pstack_push(lst2, &"you!"); */
+
+/*   char *s; */
+/*   while (!pstack_pop(lst2, &s)) { */
+/*     printf("%s\n", s); */
+/*   } */
+
+/*   pstack_destroy(lst); */
+/*   pstack_destroy(lst2); */
+
+/*   return 0; */
+/* }   */
+
+static uint64_t
+hash_name(const char* name, uint32_t element_count)
+{
+  // A multipler to use when generating a hash. Prime to hopefully avoid
+  // collisions.
+  static const uint64_t multiplier = 97;
+
+  unsigned const char* us;
+  uint64_t             hash = 0;
+
+  for (us = (unsigned const char*)name; *us; us++) {
+    hash = hash * multiplier + *us;
+  }
+
+  // Mod it against the size of the table.
+  hash %= element_count;
+
+  return hash;
+}
+
+PDSDEF void
+phash_create(uint64_t element_size,
+             uint32_t element_count,
+             void*    memory,
+             int8_t   is_pointer_type,
+             phash*   out_phash)
+{
+  if (!memory || !out_phash) {
+    fprintf(
+      stderr,
+      "phash_create failed! Pointer to memory and out_phash are required.\n");
+    return;
+  }
+  if (!element_count || !element_size) {
+    fprintf(
+      stderr,
+      "element_size and element_count must be a positive non-zero value.\n");
+    return;
+  }
+
+  out_phash->memory          = memory;
+  out_phash->element_count   = element_count;
+  out_phash->element_size    = element_size;
+  out_phash->is_pointer_type = is_pointer_type;
+  memset(out_phash->memory, 0, element_size * element_count);
+}
+
+PDSDEF void
+phash_destroy(phash* table)
+{
+  if (table) {
+    memset(table->memory, 0, table->element_size * table->element_count);
+  }
+}
+
+PDSDEF int8_t
+phash_set(phash* table, const char* name, void* value)
+{
+  if (!table || !name || !value) {
+    fprintf(stderr, "phash_set requires table, name and value to exist.");
+    return 0;
+  }
+  if (table->is_pointer_type) {
+    fprintf(stderr,
+            "phash_set should not be used with tables that have pointer types. "
+            "Use phash_set_ptr instead.\n");
+    return 0;
+  }
+
+  uint64_t hash = hash_name(name, table->element_count);
+  memcpy(
+    table->memory + (table->element_size * hash), value, table->element_size);
+  return 1;
+}
+
+PDSDEF int8_t
+phash_set_ptr(phash* table, const char* name, void** value)
+{
+  if (!table || !name) {
+    fprintf(stderr, "phash_set_ptr requires table and name  to exist.\n");
+    return 0;
+  }
+  if (!table->is_pointer_type) {
+    fprintf(stderr,
+            "phash_set_ptr should not be used with tables that do not have "
+            "pointer types. Use phash_set instead.\n");
+    return 0;
+  }
+
+  uint64_t hash                 = hash_name(name, table->element_count);
+  ((void**)table->memory)[hash] = value ? *value : 0;
+  return 1;
+}
+
+PDSDEF int8_t
+phash_get(phash* table, const char* name, void* out_value)
+{
+  if (!table || !name || !out_value) {
+    fprintf(stderr, "phash_get requires table, name and out_value to exist.\n");
+    return 0;
+  }
+  if (table->is_pointer_type) {
+    fprintf(stderr,
+            "phash_get should not be used with tables that have pointer types. "
+            "Use phash_set_ptr instead.\n");
+    return 0;
+  }
+
+  uint64_t hash = hash_name(name, table->element_count);
+  memcpy(out_value,
+         table->memory + (table->element_size * hash),
+         table->element_size);
+  return 1;
+}
+
+PDSDEF int8_t
+phash_get_ptr(phash* table, const char* name, void** out_value)
+{
+  if (!table || !name || !out_value) {
+    fprintf(stderr,
+            "phash_get_ptr requires table, name and out_value to exist.\n");
+    return 0;
+  }
+  if (!table->is_pointer_type) {
+    fprintf(stderr,
+            "phash_get_ptr should not be used with tables that do not have "
+            "pointer types. Use phash_get instead.\n");
+    return 0;
+  }
+
+  uint64_t hash = hash_name(name, table->element_count);
+  *out_value    = ((void**)table->memory)[hash];
+  return *out_value != 0;
+}
+
+/* struct test */
+/* { */
+/*   int  a; */
+/*   char b[15]; */
+/* }; */
+
+/* int */
+/* main() */
+/* { */
+/*   phash tbl; */
+/*   int   mem[2]; */
+/*   phash_create(sizeof(int), 2, &mem, 0, &tbl); */
+
+/*   int x = 2; */
+/*   phash_set(&tbl, "Val", &x); */
+/*   x = 3; */
+/*   phash_set(&tbl, "Val1", &x); */
+/*   x = 4; */
+/*   phash_set(&tbl, "Val2", &x); */
+
+/*   int y; */
+/*   phash_get(&tbl, "Val", &y); */
+/*   printf("%d\n", y); */
+/*   phash_get(&tbl, "Val1", &y); */
+/*   printf("%d\n", y); */
+/*   phash_get(&tbl, "Val2", &y); */
+/*   printf("%d\n", y); */
+
+/*   phash_destroy(&tbl); */
+
+/*   phash       tbl2; */
+/*   struct test mem2[15]; */
+/*   phash_create(sizeof(struct test), 15, &mem2, 1, &tbl2); */
+
+/*   struct test  a  = { .a = 5, .b = "Yooo" }; */
+/*   struct test* aa = &a; */
+/*   phash_set_ptr(&tbl2, "aha", (void**)&aa); */
+
+/*   struct test* get; */
+/*   phash_get_ptr(&tbl2, "aha", (void**)&get); */
+/*   printf("{ a: %d, b: %s }\n", get->a, get->b); */
+
+/*   return 0; */
+/* } */
+
+#endif /* PDS_IMPLEMENTATION */