From 25f66b395428ca99a8d7bb1d6f0c3a8eff85b88d Mon Sep 17 00:00:00 2001
From: Martin Fouilleul <martinfouilleul@gmail.com>
Date: Wed, 10 May 2023 16:25:51 +0200
Subject: [PATCH] [io, wip] read/write/seek/pos/size operations (todo: error on
 handle)

---
 samples/pong/src/main.c |  11 ++++
 src/io_common.h         |   2 +-
 src/io_impl.c           | 138 +++++++++++++++++++++++++++++++++++++++-
 3 files changed, 149 insertions(+), 2 deletions(-)

diff --git a/samples/pong/src/main.c b/samples/pong/src/main.c
index ae82918..0463c46 100644
--- a/samples/pong/src/main.c
+++ b/samples/pong/src/main.c
@@ -42,7 +42,18 @@ void OnInit(void)
 	canvas = mg_canvas_create();
 
 	file_handle file = file_open(STR8("test_file.txt")	, IO_OPEN_CREATE | IO_OPEN_WRITE);
+
+	str8 string = STR8("Hello, file!\n");
+	file_write(file, string.len, string.ptr);
 	file_close(file);
+
+	file = file_open(STR8("test_file.txt")	, IO_OPEN_READ);
+	u64 size = file_size(file);
+	char* buffer = mem_arena_alloc(mem_scratch(), size);
+	file_read(file, size, buffer);
+	file_close(file);
+
+	log_info("read file: %.*s", (int)size, buffer);
 }
 
 void OnFrameResize(u32 width, u32 height)
diff --git a/src/io_common.h b/src/io_common.h
index e7c52c8..a5fbac4 100644
--- a/src/io_common.h
+++ b/src/io_common.h
@@ -32,7 +32,7 @@ enum
 	//...
 };
 
-typedef enum { FILE_SET, FILE_END, FILE_CURR } file_whence;
+typedef enum { IO_SEEK_SET, IO_SEEK_END, IO_SEEK_CURRENT } file_whence;
 
 typedef u32 file_open_flags;
 enum {
diff --git a/src/io_impl.c b/src/io_impl.c
index 27dbe29..695d359 100644
--- a/src/io_impl.c
+++ b/src/io_impl.c
@@ -7,6 +7,7 @@
 *****************************************************************/
 
 #include<fcntl.h>
+#include<sys/stat.h>
 #include<unistd.h>
 #include"io_common.h"
 
@@ -196,6 +197,116 @@ io_cmp io_close(io_req* req)
 	return(cmp);
 }
 
+io_cmp io_size(io_req* req)
+{
+	io_cmp cmp = {0};
+	file_slot* slot = file_slot_from_handle(&__globalFileTable, req->handle);
+	if(slot)
+	{
+		struct stat s;
+		fstat(slot->fd, &s);
+		cmp.result = s.st_size;
+	}
+	else
+	{
+		cmp.error = IO_ERR_HANDLE;
+	}
+	return(cmp);
+}
+
+io_cmp io_pos(io_req* req)
+{
+	io_cmp cmp = {0};
+	file_slot* slot = file_slot_from_handle(&__globalFileTable, req->handle);
+	if(slot)
+	{
+		cmp.result = lseek(slot->fd, 0, SEEK_CUR);
+		//TODO: check for errors
+	}
+	else
+	{
+		cmp.error = IO_ERR_HANDLE;
+	}
+	return(cmp);
+}
+
+io_cmp io_seek(io_req* req)
+{
+	io_cmp cmp = {0};
+	file_slot* slot = file_slot_from_handle(&__globalFileTable, req->handle);
+	if(slot)
+	{
+		int whence;
+		switch(req->whence)
+		{
+			case IO_SEEK_CURRENT:
+				whence = SEEK_CUR;
+				break;
+
+			case IO_SEEK_SET:
+				whence = SEEK_SET;
+				break;
+
+			case IO_SEEK_END:
+				whence = SEEK_END;
+		}
+		cmp.result = lseek(slot->fd, req->size, whence);
+		//TODO: check for errors
+	}
+	else
+	{
+		cmp.error = IO_ERR_HANDLE;
+	}
+	return(cmp);
+}
+
+io_cmp io_read(io_req* req)
+{
+	io_cmp cmp = {0};
+	file_slot* slot = file_slot_from_handle(&__globalFileTable, req->handle);
+	if(slot)
+	{
+		cmp.result = read(slot->fd, req->buffer, req->size);
+		//TODO: check for errors
+	}
+	else
+	{
+		cmp.error = IO_ERR_HANDLE;
+	}
+	return(cmp);
+}
+
+io_cmp io_write(io_req* req)
+{
+	io_cmp cmp = {0};
+	file_slot* slot = file_slot_from_handle(&__globalFileTable, req->handle);
+	if(slot)
+	{
+		cmp.result = write(slot->fd, req->buffer, req->size);
+		//TODO: check for errors
+	}
+	else
+	{
+		cmp.error = IO_ERR_HANDLE;
+	}
+	return(cmp);
+}
+
+io_cmp io_get_error(io_req* req)
+{
+	io_cmp cmp = {0};
+	file_slot* slot = file_slot_from_handle(&__globalFileTable, req->handle);
+	if(slot)
+	{
+		//TODO get error from slot
+	}
+	else
+	{
+		cmp.error = IO_ERR_HANDLE;
+	}
+	return(cmp);
+}
+
 
 io_cmp io_wait_single_req(io_req* req)
 {
@@ -217,7 +328,7 @@ io_cmp io_wait_single_req(io_req* req)
 	u32 memSize = 0;
 	char* memory = (char*)m3_GetMemory(__orcaApp.runtime.m3Runtime, &memSize, 0);
 
-	u64 bufferIndex = (u64)req->buffer & 0xffffff;
+	u64 bufferIndex = (u64)req->buffer & 0xffffffff;
 
 	if(bufferIndex + req->size > memSize)
 	{
@@ -225,6 +336,7 @@ io_cmp io_wait_single_req(io_req* req)
 	}
 	else
 	{
+		//TODO: avoid modifying req.
 		req->buffer = memory + bufferIndex;
 
 		switch(req->op)
@@ -237,6 +349,30 @@ io_cmp io_wait_single_req(io_req* req)
 				cmp = io_close(req);
 				break;
 
+			case IO_OP_SIZE:
+				cmp = io_size(req);
+				break;
+
+			case IO_OP_READ:
+				cmp = io_read(req);
+				break;
+
+			case IO_OP_WRITE:
+				cmp = io_write(req);
+				break;
+
+			case IO_OP_POS:
+				cmp = io_pos(req);
+				break;
+
+			case IO_OP_SEEK:
+				cmp = io_seek(req);
+				break;
+
+			case IO_OP_ERROR:
+				cmp = io_get_error(req);
+				break;
+
 			default:
 				cmp.error = IO_ERR_INVALID;
 				break;