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 begin;
  16     size_t capacity;
  17     size_t cursor;
  18 };
  19
  20 History *create_history(size_t capacity)
  21 {
  22     Lt *lt = create_lt();
  23     if (lt == NULL) {
  24         return NULL;
  25     }
  26
  27     History *history = PUSH_LT(
  28         lt,
  29         malloc(sizeof(History)),
  30         free);
  31     if (history == NULL) {
  32         throw_error(ERROR_TYPE_LIBC);
  33         RETURN_LT(lt, NULL);
  34     }
  35     history->lt = lt;
  36
  37     history->capacity = capacity;
  38     history->begin = 0;
  39     history->cursor = 0;
  40
  41     history->buffer = PUSH_LT(lt, calloc(capacity, sizeof(char*)), free);
  42     if (history->buffer == NULL) {
  43         throw_error(ERROR_TYPE_LIBC);
  44         RETURN_LT(lt, NULL);
  45     }
  46
  47     return history;
  48 }
  49
  50 void destroy_history(History *history)
  51 {
  52     assert(history);
  53
  54     for (size_t i = 0; i < history->capacity; ++i) {
  55         if (history->buffer[i] != NULL) {
  56             free(history->buffer[i]);
  57         }
  58     }
  59
  60     RETURN_LT0(history->lt);
  61 }
  62
  63 int history_push(History *history, const char *command)
  64 {
  65     assert(history);
  66     assert(command);
  67
  68     const size_t next_begin = (history->begin + 1) % history->capacity;
  69
  70     if (history->buffer[history->begin] != NULL) {
  71         free(history->buffer[history->begin]);
  72     }
  73
  74     history->buffer[history->begin] = string_duplicate(command, NULL);
  75
  76     if (history->buffer[history->begin] == NULL) {
  77         return -1;
  78     }
  79
  80     history->begin = next_begin;
  81     history->cursor = next_begin;
  82
  83     return 0;
  84 }
  85
  86 const char *history_current(History *history)
  87 {
  88     assert(history);
  89     return history->buffer[history->cursor];
  90 }
  91
  92 void history_prev(History *history)
  93 {
  94     assert(history);
  95     if (history->cursor == 0) {
  96         history->cursor = history->capacity - 1;
  97     } else {
  98         history->cursor--;
  99     }
 100 }
 101
 102 void history_next(History *history)
 103 {
 104     assert(history);
 105     history->cursor = (history->cursor + 1) % history->capacity;
 106 }