Created a WHERE query builder and implemented a TYPE to char * method for database values

src/db_value.c

@@ -0,0 +1,188 @@
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <errno.h>
+#include <mysql.h>
+
+#include "strext.h"
+#include "db_value.h"
+
+char *db_value(char **str, size_t *len, e_column_type type, uint32_t n_args, ...)
+{
+  va_list args;
+  char *ret;
+
+  va_start(args, n_args);
+  ret = db_value_va(str, len, type, n_args, args);
+  va_end(args);
+
+  return ret;
+}
+
+char *db_value_va(char **str, size_t *len, e_column_type type, uint32_t n_args, va_list args)
+{
+  char buf[32], *tmp_str = 0, *esc_str = 0;
+  size_t tmp_len = 0, esc_len = 0;
+  MYSQL *sql;
+
+  if (n_args == 0) {
+    return 0;
+  }
+
+  memset(buf, 0, 32);
+
+  switch(type) {
+    case TYPE_BOOL:
+    {
+      sprintf(buf, "%s", va_arg(args, int) == 0 ? "FALSE" : "TRUE");
+      break;
+    }
+
+    case TYPE_INT8:
+    {
+      vsprintf(buf, "%"PRIi8, args);
+      break;
+    }
+    case TYPE_UINT8:
+    {
+      vsprintf(buf, "%"PRIu8, args);
+      break;
+    }
+
+    case TYPE_INT16:
+    {
+      vsprintf(buf, "%"PRIi16, args);
+      break;
+    }
+    case TYPE_UINT16:
+    {
+      vsprintf(buf, "%"PRIu16, args);
+      break;
+    }
+
+    case TYPE_INT32:
+    {
+      vsprintf(buf, "%"PRIi32, args);
+      break;
+    }
+    case TYPE_TIMESTAMP:
+    case TYPE_UINT32:
+    {
+      vsprintf(buf, "%"PRIu32, args);
+      break;
+    }
+
+    case TYPE_INT64:
+    {
+      vsprintf(buf, "%"PRIi64, args);
+      break;
+    }
+    case TYPE_UINT64:
+    {
+      vsprintf(buf, "%"PRIu64, args);
+      break;
+    }
+
+    case TYPE_FLOAT:
+    {
+      vsprintf(buf, "%f", args);
+      break;
+    }
+    case TYPE_DOUBLE:
+    {
+      vsprintf(buf, "%lf", args);
+      break;
+    }
+
+    case TYPE_STRING:
+    {
+      tmp_str = va_arg(args, char *);
+      if (n_args == 1) {
+        tmp_len = strlen(tmp_str);
+      } else {
+        tmp_len = va_arg(args, size_t);
+      }
+      __attribute__((fallthrough));
+    }
+    case TYPE_BLOB:
+    {
+      if (tmp_str == 0) {
+        tmp_str = (char *)va_arg(args, void *);
+        tmp_len = va_arg(args, size_t);
+      }
+
+      if (tmp_str == 0) {
+        esc_str = (char *)malloc(5);
+        if (esc_str == 0) {
+          fprintf(stderr, "[%d]malloc: (%d) %s\n", __LINE__, errno, strerror(errno));
+          return 0;
+        }
+        memcpy(esc_str, "NULL", 4);
+        esc_str[4] = '\0';
+        esc_len = 4;
+        break;
+      }
+
+      sql = mysql_init(NULL);
+      if (sql == 0) {
+        fprintf(stderr, "[%d]mysql_init: (%d) %s\n", __LINE__, errno, strerror(errno));
+        return 0;
+      }
+
+      esc_str = (char *)malloc(tmp_len * 2 + 1 + 2);
+      if (esc_str == 0) {
+        fprintf(stderr, "[%d]malloc: (%d) %s\n", __LINE__, errno, strerror(errno));
+        mysql_close(sql);
+        return 0;
+      }
+
+
+      esc_str[0] = '\'';
+      esc_len = mysql_real_escape_string(sql, esc_str + 1, tmp_str, tmp_len);
+      esc_str[esc_len + 1] = '\'';
+      esc_str[esc_len + 2] = '\0';
+      esc_len += 2;
+      mysql_close(sql);
+
+      tmp_str = esc_str;
+      esc_str = (char *)realloc(esc_str, esc_len + 1);
+      if (esc_str == 0) {
+        fprintf(stderr, "[%d]realloc: (%d) %s\n", __LINE__, errno, strerror(errno));
+        return 0;
+      }
+
+      break;
+    }
+
+    case TYPE_RAW:
+    {
+      tmp_str = va_arg(args, char *);
+      tmp_len = va_arg(args, size_t);
+
+      esc_str = (char *)malloc(tmp_len + 1);
+      if (esc_str == 0) {
+        fprintf(stderr, "[%d]malloc: (%d) %s\n", __LINE__, errno, strerror(errno));
+        return 0;
+      }
+      memcpy(esc_str, tmp_str, tmp_len);
+      esc_str[tmp_len] = '\0';
+
+      break;
+    }
+  }
+
+  if (esc_str == 0) {
+    if (strmemcpy(buf, strlen(buf), &esc_str, &esc_len) != 0) {
+      return 0;
+    }
+  }
+
+  if (str != 0) {
+    *str = esc_str;
+    *len = esc_len;
+  }
+
+  return esc_str;
+}