From b3892cb6e4963e1bbeb346a8124101b7c3cf379b Mon Sep 17 00:00:00 2001
From: David Robillard <d@drobilla.net>
Date: Sat, 14 Aug 2021 01:51:55 -0400
Subject: Simplify input stream API

More or less the same rationale as the previous commit, but for reading.  This
makes for nice symmetry with writing, at the cost of a slightly more annoying
reader interface since the source doesn't know its block size or name.
---
 src/input_stream.c | 150 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 150 insertions(+)
 create mode 100644 src/input_stream.c

(limited to 'src/input_stream.c')

diff --git a/src/input_stream.c b/src/input_stream.c
new file mode 100644
index 00000000..42dfc6f8
--- /dev/null
+++ b/src/input_stream.c
@@ -0,0 +1,150 @@
+/*
+  Copyright 2011-2021 David Robillard <d@drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "serd_config.h"
+
+#include "serd/serd.h"
+
+#include <sys/stat.h>
+
+#if USE_POSIX_FADVISE && USE_FILENO
+#  include <fcntl.h>
+#endif
+
+// IWYU pragma: no_include <features.h>
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+static size_t
+serd_string_read(void* const  buf,
+                 const size_t size,
+                 const size_t nmemb,
+                 void* const  stream)
+{
+  const char** position = (const char**)stream;
+
+  size_t       n_read = 0u;
+  const size_t len    = size * nmemb;
+  while (n_read < len && **position) {
+    ((char*)buf)[n_read++] = **position;
+
+    ++(*position);
+  }
+
+  return n_read;
+}
+
+static int
+serd_string_error(void* const stream)
+{
+  (void)stream;
+  return 0;
+}
+
+static int
+serd_string_close(void* const stream)
+{
+  (void)stream;
+  return 0;
+}
+
+SerdInputStream
+serd_open_input_stream(SerdReadFunc SERD_NONNULL         read_func,
+                       SerdStreamErrorFunc SERD_NONNULL  error_func,
+                       SerdStreamCloseFunc SERD_NULLABLE close_func,
+                       void* const                       stream)
+{
+  assert(read_func);
+  assert(error_func);
+
+  SerdInputStream input = {stream, read_func, error_func, close_func};
+  return input;
+}
+
+static bool
+is_directory(const char* const path)
+{
+#ifdef _MSC_VER
+  struct stat st;
+  return !stat(path, &st) && (st.st_mode & _S_IFDIR);
+#else
+  struct stat st;
+  return !stat(path, &st) && S_ISDIR(st.st_mode);
+#endif
+}
+
+SerdInputStream
+serd_open_input_string(const char** const position)
+{
+  assert(position);
+  assert(*position);
+
+  const SerdInputStream input = {
+    position, serd_string_read, serd_string_error, serd_string_close};
+
+  return input;
+}
+
+SerdInputStream
+serd_open_input_file(const char* const path)
+{
+  assert(path);
+
+  SerdInputStream input = {NULL, NULL, NULL, NULL};
+  if (is_directory(path)) {
+    return input;
+  }
+
+#ifdef __GLIBC__
+  FILE* const file = fopen(path, "rbe");
+#else
+  FILE* const file = fopen(path, "rb");
+#endif
+
+  if (!file) {
+    return input;
+  }
+
+#if USE_POSIX_FADVISE && USE_FILENO
+  posix_fadvise(fileno(file), 0, 0, POSIX_FADV_SEQUENTIAL);
+#endif
+
+  input.stream = file;
+  input.read   = (SerdReadFunc)fread;
+  input.error  = (SerdStreamErrorFunc)ferror;
+  input.close  = (SerdStreamCloseFunc)fclose;
+
+  return input;
+}
+
+SerdStatus
+serd_close_input(SerdInputStream* const input)
+{
+  int ret = 0;
+
+  if (input) {
+    if (input->close && input->stream) {
+      ret           = input->close(input->stream);
+      input->stream = NULL;
+    }
+
+    input->stream = NULL;
+  }
+
+  return ret ? SERD_ERR_UNKNOWN : SERD_SUCCESS;
+}
-- 
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