src/ui/history.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <assert.h>
   4
   5 #include "history.h"
   6 #include "system/lt.h"
   7 #include "system/error.h"
   8 #include "str.h"
   9
  10 struct History
  11 {
  12     Lt *lt;
  13
  14     char **buffer;
  15     size_t cursor;
  16     size_t capacity;
  17 };
  18
  19 History *create_history(size_t capacity)
  20 {
  21     Lt *lt = create_lt();
  22     if (lt == NULL) {
  23         return NULL;
  24     }
  25
  26     History *history = PUSH_LT(
  27         lt,
  28         malloc(sizeof(History)),
  29         free);
  30     if (history == NULL) {
  31         throw_error(ERROR_TYPE_LIBC);
  32         RETURN_LT(lt, NULL);
  33     }
  34     history->lt = lt;
  35
  36     history->capacity = capacity;
  37     history->cursor = 0;
  38
  39     history->buffer = PUSH_LT(lt, calloc(capacity, sizeof(char*)), free);
  40     if (history->buffer == NULL) {
  41         throw_error(ERROR_TYPE_LIBC);
  42         RETURN_LT(lt, NULL);
  43     }
  44
  45     return history;
  46 }
  47
  48 void destroy_history(History *history)
  49 {
  50     assert(history);
  51
  52     for (size_t i = 0; i < history->capacity; ++i) {
  53         if (history->buffer[i] != NULL) {
  54             free(history->buffer[i]);
  55         }
  56     }
  57
  58     RETURN_LT0(history->lt);
  59 }
  60
  61 int history_push(History *history, const char *command)
  62 {
  63     assert(history);
  64     assert(command);
  65
  66     const size_t next_cursor = (history->cursor + 1) % history->capacity;
  67
  68     if (history->buffer[history->cursor] != NULL) {
  69         free(history->buffer[history->cursor]);
  70     }
  71
  72     history->buffer[history->cursor] = string_duplicate(command, NULL);
  73
  74     if (history->buffer[history->cursor] == NULL) {
  75         return -1;
  76     }
  77
  78     history->cursor = next_cursor;
  79
  80     return 0;
  81 }
  82
  83 const char *history_get(History *history, size_t i)
  84 {
  85     assert(history);
  86     return history->buffer[(history->cursor + i) % history->capacity];
  87 }