libioutil Implement a file reader

ce/ce.c

@@ -1,5 +1,6 @@
 #include <arena.h>
 #include <desc.h>
+#include <filereader.h>
 #include <filewriter.h>
 #include <liballoc.h>
 #include <list.h>
@@ -386,7 +387,6 @@ static void mkfile (struct context* context, char** file_paths, size_t files_cou
 }
 
 static void cat (struct context* context, char** file_paths, size_t files_count) {
-  struct desc desc;
   char volume[VOLUME_MAX];
   const char* path;
   int ret;
@@ -399,29 +399,39 @@ static void cat (struct context* context, char** file_paths, size_t files_count)
       continue;
     }
 
-    if ((ret = volume_open (volume)) < 0) {
-      cprintf (context, "ERROR could not open volume '%s': %s\n", volume, str_status[-ret]);
-      continue;
+    struct filereader fr;
+    if ((ret = filereader_init (&fr, volume, path)) < 0) {
+      cprintf (context, "ERROR could not initialize filereader for '%s:%s'\n", volume, path);
+      return;
     }
 
-    describe (path, &desc);
+    size_t chunk_size = 1024;
+    char* buffer = arena_malloc (&arena, chunk_size);
 
-    if (desc.type != FS_FILE)
-      goto close;
+    size_t chunks = fr.file_size / chunk_size;
+    size_t rem = fr.file_size % chunk_size;
 
-    char* buffer = malloc (desc.size + 1);
+    for (size_t chunk = 0; chunk < chunks; chunk++) {
+      if ((ret = filereader_read (&fr, (uint8_t*)buffer, chunk_size)) < 0) {
+        filereader_fini (&fr);
+        cprintf (context, "ERROR filereader failed to read from '%s:%s'\n", volume, path);
+        return;
+      }
 
-    if (buffer == NULL)
-      goto close;
+      mail_send (e_pgid, buffer, chunk_size);
+    }
 
-    memset (buffer, 0, desc.size + 1);
-    read_file (path, 0, (uint8_t*)buffer, desc.size);
-    cprintf (context, "%s\n", buffer);
+    if (rem > 0) {
+      if ((ret = filereader_read (&fr, (uint8_t*)buffer, rem)) < 0) {
+        filereader_fini (&fr);
+        cprintf (context, "ERROR filereader failed to read from '%s:%s'\n", volume, path);
+        return;
+      }
 
-  close:
-    if (buffer != NULL)
-      free (buffer);
-    volume_close ();
+      mail_send (e_pgid, buffer, rem);
+    }
+
+    filereader_fini (&fr);
   }
 }
 
@@ -566,12 +576,14 @@ static void execute_redir (struct ast_redir* redir, struct context* context) {
     }
   }
 
+  if (rem > 0) {
     if ((ret = filewriter_write (&fw, (uint8_t*)&context->strbuf.items[chunks * chunk_size], rem)) <
         0) {
       filewriter_fini (&fw);
       cprintf (context, "ERROR filewriter failed to write to '%s:%s'\n", volume, path);
       return;
     }
+  }
 
   filewriter_fini (&fw);
 }

libioutil/filereader.c

@@ -0,0 +1,61 @@
+#include <desc.h>
+#include <filereader.h>
+#include <path_defs.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <system.h>
+
+int filereader_init (struct filereader* fw, const char* volume, const char* path) {
+  memset (fw, 0, sizeof (*fw));
+  strncpy (fw->volume, volume, VOLUME_MAX);
+  strncpy (fw->path, path, PATH_MAX);
+
+  int ret;
+  struct desc desc;
+
+  if ((ret = volume_open (fw->volume)) < 0)
+    return -FR_VOLUME_OPEN_ERROR;
+
+  if ((ret = describe (fw->path, &desc)) < 0) {
+    volume_close ();
+    return -FR_DESC_ERROR;
+  }
+
+  if (desc.type != FS_FILE)
+    return -FR_NOT_FILE;
+
+  fw->file_size = desc.size;
+  fw->flags |= FR_OPEN;
+
+  return FR_OK;
+}
+
+int filereader_fini (struct filereader* fw) {
+  if ((fw->flags & FR_OPEN)) {
+    volume_close ();
+    fw->flags &= ~FR_OPEN;
+  }
+
+  return FR_OK;
+}
+
+int filereader_read (struct filereader* fw, uint8_t* buffer, size_t buffer_size) {
+  if (!(fw->flags & FR_OPEN))
+    return -FR_VOLUME_NOT_OPENED;
+
+  int ret;
+
+  if (buffer_size > 0) {
+    if (!(fw->read_cursor + buffer_size <= fw->file_size))
+      return -FR_CURSOR_OOB;
+
+    if ((ret = read_file (fw->path, fw->read_cursor, buffer, buffer_size)) < 0)
+      return -FR_READ_ERROR;
+
+    fw->read_cursor += buffer_size;
+  }
+
+  return FR_OK;
+}

libioutil/filereader.h

@@ -0,0 +1,33 @@
+#ifndef _LIBIOUTIL_FILEREADER_H
+#define _LIBIOUTIL_FILEREADER_H
+
+#include <path_defs.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#define FR_OK                0
+#define FR_VOLUME_OPEN_ERROR 1
+#define FR_DESC_ERROR        2
+#define FR_NOT_FILE          3
+#define FR_VOLUME_NOT_OPENED 4
+#define FR_READ_ERROR        5
+#define FR_CURSOR_OOB        6
+
+#define FR_OPEN (1 << 31)
+
+struct filereader {
+  char volume[VOLUME_MAX];
+  char path[PATH_MAX];
+  size_t read_cursor;
+  size_t file_size;
+  uint32_t flags;
+};
+
+int filereader_init (struct filereader* fw, const char* volume, const char* path);
+
+int filereader_fini (struct filereader* fw);
+
+int filereader_read (struct filereader* fw, uint8_t* buffer, size_t buffer_size);
+
+#endif // _LIBIOUTIL_FILEREADER_H

libioutil/src.mk

@@ -1,3 +1,5 @@
-c += filewriter.c
+c += filewriter.c \
+		 filereader.c
 
-o += filewriter.o
+o += filewriter.o \
+		 filereader.o