1 files changed, 103 insertions, 0 deletions
diff --git a/kit/input_stream.c b/kit/input_stream.c
new file mode 100644
index 0000000..369cf64
--- /dev/null
+++ b/kit/input_stream.c
@@ -0,0 +1,103 @@
+#include "input_stream.h"
+
+#include <string.h>
+
+enum { KIT_INPUT_STREAM_STR, KIT_INPUT_STREAM_FILE };
+
+typedef struct {
+  i64              type;
+  kit_allocator_t *alloc;
+} kit_is_state_basic_t;
+
+typedef struct {
+  i64              type;
+  kit_allocator_t *alloc;
+  kit_str_t        string;
+} kit_is_state_str_t;
+
+typedef struct {
+  i64              type;
+  kit_allocator_t *alloc;
+  FILE            *file;
+} kit_is_state_file_t;
+
+static int kit_is_check_type_(void *state, i64 type) {
+  kit_is_state_basic_t *basic = (kit_is_state_basic_t *) state;
+  return basic != NULL && basic->type == type;
+}
+
+static i64 kit_read_str_(void *state, kit_str_t destination) {
+  if (!kit_is_check_type_(state, KIT_INPUT_STREAM_STR))
+    return 0;
+
+  kit_is_state_str_t *str = (kit_is_state_str_t *) state;
+  i64 size = destination.size < str->string.size ? destination.size
+                                                 : str->string.size;
+  memcpy(destination.values, str->string.values, size);
+  str->string.values += size;
+  str->string.size -= size;
+  return size;
+}
+
+static i64 kit_read_file_(void *state, kit_str_t destination) {
+  if (!kit_is_check_type_(state, KIT_INPUT_STREAM_FILE))
+    return 0;
+
+  kit_is_state_file_t *f = (kit_is_state_file_t *) state;
+
+  if (f->file == NULL || feof(f->file))
+    return 0;
+
+  i64 size = (i64) fread(destination.values, 1, destination.size,
+                         f->file);
+
+  if (size <= 0)
+    return 0;
+
+  return size;
+}
+
+kit_is_handle_t kit_is_wrap_string(kit_str_t        string,
+                                   kit_allocator_t *alloc) {
+  kit_is_handle_t in;
+  memset(&in, 0, sizeof in);
+
+  kit_is_state_str_t *state = (kit_is_state_str_t *)
+      kit_alloc_dispatch(alloc, KIT_ALLOCATE,
+                         sizeof(kit_is_state_str_t), 0, NULL);
+  if (state != NULL) {
+    memset(state, 0, sizeof *state);
+    state->type   = KIT_INPUT_STREAM_STR;
+    state->string = string;
+    state->alloc  = alloc;
+    in.state      = state;
+    in.read       = kit_read_str_;
+  }
+  return in;
+}
+
+kit_is_handle_t kit_is_wrap_file(FILE *f, kit_allocator_t *alloc) {
+  kit_is_handle_t in;
+  memset(&in, 0, sizeof in);
+
+  kit_is_state_file_t *state = (kit_is_state_file_t *)
+      kit_alloc_dispatch(alloc, KIT_ALLOCATE,
+                         sizeof(kit_is_state_file_t), 0, NULL);
+
+  if (state != NULL) {
+    memset(state, 0, sizeof *state);
+    state->type  = KIT_INPUT_STREAM_FILE;
+    state->file  = f;
+    state->alloc = alloc;
+    in.state     = state;
+    in.read      = kit_read_file_;
+  }
+
+  return in;
+}
+
+void kit_is_destroy(kit_is_handle_t in) {
+  kit_is_state_basic_t *basic = (kit_is_state_basic_t *) in.state;
+  if (basic != NULL)
+    kit_alloc_dispatch(basic->alloc, KIT_DEALLOCATE, 0, 0, in.state);
+}