3 files changed, 135 insertions, 83 deletions

diff --git a/src/io/read_file.c b/src/io/read_file.c
new file mode 100644
index 0000000..b2f4604
--- /dev/null
+++ b/src/io/read_file.c
@@ -0,0 +1,94 @@
+#include <fcntl.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "read_file.h"
+
+#define CHECK_OOM(ptr) \
+  if (ptr == NULL) { \
+    fprintf(stderr, "geheugen is op"); \
+    /* I think I should free the original memory here, but whatever */ \
+    return NULL; \
+  }
+
+struct filebuf *stream_to_filebuf(FILE *restrict stream) {
+  size_t sz = 0;
+  size_t cap = 4096;
+  char *buf = malloc(cap);
+  CHECK_OOM(buf);
+
+  while (!feof(stream)) {
+    if (cap-sz == 0) {
+      cap *= 2;
+      buf = realloc(buf, cap);
+      CHECK_OOM(buf);
+    }
+
+    const size_t amount = cap-sz;
+    const size_t n = fread(buf+sz, 1, amount, stream);
+    sz += n;
+
+    if (n != amount && !feof(stream)) {
+      fprintf(stderr, "fout tijdens lezen van standaard invoer.\n");
+      free(buf);
+      return NULL;
+    }
+  }
+
+  buf = realloc(buf, sz);
+
+  struct filebuf *res = calloc(1, sizeof(struct filebuf));
+  res->buf = buf;
+  res->sz = sz;
+  res->mapping_type = MT_MMAP;
+  return res;
+}
+
+static void *fd_to_mmap(const int fd, struct stat sb) {
+  void *addr = mmap(NULL, sb.st_size, PROT_READ, MAP_SHARED, fd, 0);
+  if (addr == MAP_FAILED) {
+    return NULL;
+  }
+
+  close(fd);
+  return addr;
+}
+
+struct filebuf *file_to_filebuf(char *fname) {
+  const int fd = open(fname, O_RDONLY);
+
+  struct stat sb;
+  if (fstat(fd, &sb) == -1) {
+    goto stream;
+  }
+
+  void *addr;
+  if ((addr = fd_to_mmap(fd, sb)) != NULL) {
+    struct filebuf *res = calloc(1, sizeof(struct filebuf));
+    res->buf = addr;
+    res->sz = sb.st_size;
+    res->mapping_type = MT_MMAP;
+    return res;
+  }
+
+stream: {
+  FILE *stream = fdopen(fd, "rb");
+  struct filebuf *res = stream_to_filebuf(stream);
+  fclose(stream);
+  return res;
+}
+}
+
+void free_filebuf(struct filebuf *fb) {
+  switch (fb->mapping_type) {
+    case MT_MMAP:
+      munmap(fb->buf, fb->sz);
+      break;
+    case MT_OWNED:
+      free(fb->buf);
+      break;
+  }
+  free(fb);
+}
diff --git a/src/io/read_file.h b/src/io/read_file.h
new file mode 100644
index 0000000..201ae5b
--- /dev/null
+++ b/src/io/read_file.h
@@ -0,0 +1,19 @@
+#pragma once
+
+#include <stddef.h>
+#include <stdio.h>
+
+enum mapping_type {
+  MT_MMAP,
+  MT_OWNED,
+};
+
+struct filebuf {
+  char *buf;
+  size_t sz;
+  enum mapping_type mapping_type;
+};
+
+struct filebuf *stream_to_filebuf(FILE *restrict stream);
+struct filebuf *file_to_filebuf(char *fname);
+void free_filebuf(struct filebuf *filebuf);
diff --git a/src/tak.c b/src/tak.c
index e970ae1..e8fb817 100644
--- a/src/tak.c
+++ b/src/tak.c
@@ -6,6 +6,7 @@
 
 #include "util/map.h"
 #include "util/versie.h"
+#include "io/read_file.h"
 
 static void usage(FILE *f) {
   fprintf(f,
@@ -39,25 +40,20 @@ static char** parse_options(int argc, char **argv) {
   return argv + optind;
 }
 
-struct state {
-  char *buf;
-  size_t sz;
-};
-
-static void process(struct state state) {
+static void process(struct filebuf *fb) {
   char *lstart, *lend;
-  lend = &state.buf[state.sz - 1];
+  lend = &fb->buf[fb->sz - 1];
 
-  while (lend > state.buf) {
+  while (lend > fb->buf) {
     if (*lend == '\n') {
       lend--;
     }
 
     lstart = lend;
-    while (*lstart != '\n' && lstart != state.buf) {
+    while (*lstart != '\n' && lstart != fb->buf) {
       lstart--;
     }
-    if (lstart != state.buf) {
+    if (lstart != fb->buf) {
       lstart++;
     }
 
@@ -65,96 +61,39 @@ static void process(struct state state) {
 
     lend = lstart-1;
   }
-}
-
-#define CHECK_OOM(ptr) \
-  if (ptr == NULL) { \
-    fprintf(stderr, "tak: geheugen is op"); \
-    /* I think I should free the original memory here, but whatever */ \
-    return NULL; \
-  }
 
-static char *read_stream(FILE *stream, size_t *sz) {
-  *sz = 0;
-  size_t cap = 4096;
-  char *res = malloc(cap);
-  CHECK_OOM(res);
-
-  while (!feof(stream)) {
-    if (cap-*sz == 0) {
-      cap *= 2;
-      res = realloc(res, cap);
-      CHECK_OOM(res);
-    }
-
-    const size_t amount = cap-*sz;
-    const size_t n = fread(res+*sz, 1, amount, stream);
-    *sz += n;
-
-    if (n != amount && !feof(stream)) {
-      fprintf(stderr, "tak: fout tijdens lezen van standaard invoer.\n");
-      free(res);
-      return NULL;
-    }
-  }
-
-  res = realloc(res, *sz);
-  return res;
-}
-
-int handleStream(FILE *stream) {
-  size_t sz = 0;
-  char *data = read_stream(stream, &sz);
-  if (data == NULL) {
-    return 1;
-  }
-
-  struct state state = { .buf = data, .sz = sz };
-  process(state);
-
-  free(data);
-  return 0;
-}
-
-int handleFile(char *fname) {
-  struct map *map = open_map(fname);
-  if (map == NULL) {
-    return 1;
-  }
-
-  struct state state = { .buf = map->addr, .sz = map->sb.st_size };
-  process(state);
-
-  close_map(map);
-
-  return 0;
+  free_filebuf(fb);
 }
 
 int entry_tak(int argc, char **argv) {
   char **args = parse_options(argc, argv);
 
   if (*args == NULL) {
-    handleStream(stdin);
+    struct filebuf *fb = stream_to_filebuf(stdin);
+    if (fb == NULL) {
+      return 1;
+    }
+
+    process(fb);
     return 0;
   }
 
   while (*args != NULL) {
+    struct filebuf *fb = NULL;
+
     if (!strcmp(*args, "-")) {
-      handleStream(stdin);
-      goto next;
+      fb = stream_to_filebuf(stdin);
+      if (fb == NULL) {
+        return 1;
+      }
     }
 
-    if (!handleFile(*args)) {
-      goto next;
+    if (fb == NULL) {
+      fb = file_to_filebuf(*args);
     }
 
-    FILE *stream = fopen(*args, "rb");
-    if (handleStream(stream)) {
-      return 1;
-    }
-    fclose(stream);
+    process(fb);
 
-next:
     args++;
   }