Adding third party library hidapi

third_party/hidapi/hidapi_win.c

+/*******************************************************
+ HIDAPI - Multi-Platform library for
+ communication with HID devices.
+
+ Alan Ott
+ Signal 11 Software
+
+ 8/22/2009
+
+ Copyright 2009, All Rights Reserved.
+
+ At the discretion of the user of this library,
+ this software may be licensed under the terms of the
+ GNU General Public License v3, a BSD-Style license, or the
+ original HIDAPI license as outlined in the LICENSE.txt,
+ LICENSE-gpl3.txt, LICENSE-bsd.txt, and LICENSE-orig.txt
+ files located at the root of the source distribution.
+ These files may also be found in the public source
+ code repository located at:
+        http://github.com/signal11/hidapi .
+********************************************************/
+
+#include <windows.h>
+
+#ifndef _NTDEF_
+typedef LONG NTSTATUS;
+#endif
+
+#ifdef __MINGW32__
+#include <ntdef.h>
+#include <winbase.h>
+#endif
+
+#ifdef __CYGWIN__
+#include <ntdef.h>
+#define _wcsdup wcsdup
+#endif
+
+/*#define HIDAPI_USE_DDK*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+        #include <setupapi.h>
+        #include <winioctl.h>
+        #ifdef HIDAPI_USE_DDK
+                #include <hidsdi.h>
+        #endif
+
+        /* Copied from inc/ddk/hidclass.h, part of the Windows DDK. */
+        #define HID_OUT_CTL_CODE(id)  \
+                CTL_CODE(FILE_DEVICE_KEYBOARD, (id), METHOD_OUT_DIRECT, FILE_ANY_ACCESS)
+        #define IOCTL_HID_GET_FEATURE                   HID_OUT_CTL_CODE(100)
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+
+
+#include "hidapi.h"
+
+#ifdef _MSC_VER
+        /* Thanks Microsoft, but I know how to use strncpy(). */
+        #pragma warning(disable:4996)

[Will Harris, 2014/01/14 23:40:01]

prefer to disable in the gyp file rather than inline

+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef HIDAPI_USE_DDK
+        /* Since we're not building with the DDK, and the HID header
+           files aren't part of the SDK, we have to define all this
+           stuff here. In lookup_functions(), the function pointers
+           defined below are set. */
+        typedef struct _HIDD_ATTRIBUTES{
+                ULONG Size;
+                USHORT VendorID;
+                USHORT ProductID;
+                USHORT VersionNumber;
+        } HIDD_ATTRIBUTES, *PHIDD_ATTRIBUTES;
+
+        typedef USHORT USAGE;
+        typedef struct _HIDP_CAPS {
+                USAGE Usage;
+                USAGE UsagePage;
+                USHORT InputReportByteLength;
+                USHORT OutputReportByteLength;
+                USHORT FeatureReportByteLength;
+                USHORT Reserved[17];
+                USHORT fields_not_used_by_hidapi[10];
+        } HIDP_CAPS, *PHIDP_CAPS;
+        typedef void* PHIDP_PREPARSED_DATA;
+        #define HIDP_STATUS_SUCCESS 0x110000
+
+        typedef BOOLEAN (__stdcall *HidD_GetAttributes_)(HANDLE device, PHIDD_ATTRIBUTES attrib);
+        typedef BOOLEAN (__stdcall *HidD_GetSerialNumberString_)(HANDLE device, PVOID buffer, ULONG buffer_len);
+        typedef BOOLEAN (__stdcall *HidD_GetManufacturerString_)(HANDLE handle, PVOID buffer, ULONG buffer_len);
+        typedef BOOLEAN (__stdcall *HidD_GetProductString_)(HANDLE handle, PVOID buffer, ULONG buffer_len);
+        typedef BOOLEAN (__stdcall *HidD_SetFeature_)(HANDLE handle, PVOID data, ULONG length);
+        typedef BOOLEAN (__stdcall *HidD_GetFeature_)(HANDLE handle, PVOID data, ULONG length);
+        typedef BOOLEAN (__stdcall *HidD_GetIndexedString_)(HANDLE handle, ULONG string_index, PVOID buffer, ULONG buffer_len);
+        typedef BOOLEAN (__stdcall *HidD_GetPreparsedData_)(HANDLE handle, PHIDP_PREPARSED_DATA *preparsed_data);
+        typedef BOOLEAN (__stdcall *HidD_FreePreparsedData_)(PHIDP_PREPARSED_DATA preparsed_data);
+        typedef NTSTATUS (__stdcall *HidP_GetCaps_)(PHIDP_PREPARSED_DATA preparsed_data, HIDP_CAPS *caps);
+
+        static HidD_GetAttributes_ HidD_GetAttributes;
+        static HidD_GetSerialNumberString_ HidD_GetSerialNumberString;
+        static HidD_GetManufacturerString_ HidD_GetManufacturerString;
+        static HidD_GetProductString_ HidD_GetProductString;
+        static HidD_SetFeature_ HidD_SetFeature;
+        static HidD_GetFeature_ HidD_GetFeature;
+        static HidD_GetIndexedString_ HidD_GetIndexedString;
+        static HidD_GetPreparsedData_ HidD_GetPreparsedData;
+        static HidD_FreePreparsedData_ HidD_FreePreparsedData;
+        static HidP_GetCaps_ HidP_GetCaps;
+
+        static HMODULE lib_handle = NULL;
+        static BOOLEAN initialized = FALSE;
+#endif /* HIDAPI_USE_DDK */
+
+struct hid_device_ {
+                HANDLE device_handle;
+                BOOL blocking;
+                USHORT output_report_length;
+                size_t input_report_length;
+                void *last_error_str;
+                DWORD last_error_num;
+                BOOL read_pending;
+                char *read_buf;
+                OVERLAPPED ol;
+};
+
+static hid_device *new_hid_device()
+{
+        hid_device *dev = (hid_device*) calloc(1, sizeof(hid_device));
+        dev->device_handle = INVALID_HANDLE_VALUE;
+        dev->blocking = TRUE;
+        dev->output_report_length = 0;
+        dev->input_report_length = 0;
+        dev->last_error_str = NULL;
+        dev->last_error_num = 0;
+        dev->read_pending = FALSE;
+        dev->read_buf = NULL;
+        memset(&dev->ol, 0, sizeof(dev->ol));
+        dev->ol.hEvent = CreateEvent(NULL, FALSE, FALSE /*inital state f=nonsignaled*/, NULL);
+
+        return dev;
+}
+
+static void free_hid_device(hid_device *dev)
+{
+        CloseHandle(dev->ol.hEvent);
+        CloseHandle(dev->device_handle);
+        LocalFree(dev->last_error_str);
+        free(dev->read_buf);
+        free(dev);
+}
+
+static void register_error(hid_device *device, const char *op)
+{
+        WCHAR *ptr, *msg;
+
+        FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
+                FORMAT_MESSAGE_FROM_SYSTEM |
+                FORMAT_MESSAGE_IGNORE_INSERTS,
+                NULL,
+                GetLastError(),
+                MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+                (LPVOID)&msg, 0/*sz*/,
+                NULL);
+        
+        /* Get rid of the CR and LF that FormatMessage() sticks at the
+           end of the message. Thanks Microsoft! */
+        ptr = msg;
+        while (*ptr) {
+                if (*ptr == '\r') {
+                        *ptr = 0x0000;
+                        break;
+                }
+                ptr++;
+        }
+
+        /* Store the message off in the Device entry so that
+           the hid_error() function can pick it up. */
+        LocalFree(device->last_error_str);
+        device->last_error_str = msg;
+}
+
+#ifndef HIDAPI_USE_DDK
+static int lookup_functions()
+{
+        lib_handle = LoadLibraryA("hid.dll");

[Will Harris, 2014/01/14 23:40:01]

where will this code be called from?  Prefer not to have random LoadLibary
happening.

Can you get the HIDAPI_USE_DDK define to work to avoid this?

+        if (lib_handle) {
+#define RESOLVE(x) x = (x##_)GetProcAddress(lib_handle, #x); if (!x) return -1;
+                RESOLVE(HidD_GetAttributes);
+                RESOLVE(HidD_GetSerialNumberString);
+                RESOLVE(HidD_GetManufacturerString);
+                RESOLVE(HidD_GetProductString);
+                RESOLVE(HidD_SetFeature);
+                RESOLVE(HidD_GetFeature);
+                RESOLVE(HidD_GetIndexedString);
+                RESOLVE(HidD_GetPreparsedData);
+                RESOLVE(HidD_FreePreparsedData);
+                RESOLVE(HidP_GetCaps);
+#undef RESOLVE
+        }
+        else
+                return -1;
+
+        return 0;
+}
+#endif
+
+static HANDLE open_device(const char *path, BOOL enumerate)
+{
+        HANDLE handle;
+        DWORD desired_access = (enumerate)? 0: (GENERIC_WRITE | GENERIC_READ);
+        DWORD share_mode = (enumerate)?
+                              FILE_SHARE_READ|FILE_SHARE_WRITE:
+                              FILE_SHARE_READ;
+
+        handle = CreateFileA(path,
+                desired_access,
+                share_mode,
+                NULL,
+                OPEN_EXISTING,
+                FILE_FLAG_OVERLAPPED,/*FILE_ATTRIBUTE_NORMAL,*/
+                0);
+
+        return handle;
+}
+
+int HID_API_EXPORT hid_init(void)
+{
+#ifndef HIDAPI_USE_DDK
+        if (!initialized) {
+                if (lookup_functions() < 0) {
+                        hid_exit();
+                        return -1;
+                }
+                initialized = TRUE;
+        }
+#endif
+        return 0;
+}
+
+int HID_API_EXPORT hid_exit(void)
+{
+#ifndef HIDAPI_USE_DDK
+        if (lib_handle)
+                FreeLibrary(lib_handle);
+        lib_handle = NULL;
+        initialized = FALSE;
+#endif
+        return 0;
+}
+
+struct hid_device_info HID_API_EXPORT * HID_API_CALL hid_enumerate(unsigned short vendor_id, unsigned short product_id)
+{
+        BOOL res;
+        struct hid_device_info *root = NULL; /* return object */
+        struct hid_device_info *cur_dev = NULL;
+
+        /* Windows objects for interacting with the driver. */
+        GUID InterfaceClassGuid = {0x4d1e55b2, 0xf16f, 0x11cf, {0x88, 0xcb, 0x00, 0x11, 0x11, 0x00, 0x00, 0x30} };
+        SP_DEVINFO_DATA devinfo_data;
+        SP_DEVICE_INTERFACE_DATA device_interface_data;
+        SP_DEVICE_INTERFACE_DETAIL_DATA_A *device_interface_detail_data = NULL;
+        HDEVINFO device_info_set = INVALID_HANDLE_VALUE;
+        int device_index = 0;
+        int i;
+
+        if (hid_init() < 0)
+                return NULL;
+
+        /* Initialize the Windows objects. */
+        memset(&devinfo_data, 0x0, sizeof(devinfo_data));
+        devinfo_data.cbSize = sizeof(SP_DEVINFO_DATA);
+        device_interface_data.cbSize = sizeof(SP_DEVICE_INTERFACE_DATA);
+
+        /* Get information for all the devices belonging to the HID class. */
+        device_info_set = SetupDiGetClassDevsA(&InterfaceClassGuid, NULL, NULL, DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);
+        
+        /* Iterate over each device in the HID class, looking for the right one. */
+        
+        for (;;) {
+                HANDLE write_handle = INVALID_HANDLE_VALUE;
+                DWORD required_size = 0;
+                HIDD_ATTRIBUTES attrib;
+
+                res = SetupDiEnumDeviceInterfaces(device_info_set,
+                        NULL,
+                        &InterfaceClassGuid,
+                        device_index,
+                        &device_interface_data);
+                
+                if (!res) {
+                        /* A return of FALSE from this function means that
+                           there are no more devices. */
+                        break;
+                }
+
+                /* Call with 0-sized detail size, and let the function
+                   tell us how long the detail struct needs to be. The
+                   size is put in &required_size. */
+                res = SetupDiGetDeviceInterfaceDetailA(device_info_set,
+                        &device_interface_data,
+                        NULL,
+                        0,
+                        &required_size,
+                        NULL);
+
+                /* Allocate a long enough structure for device_interface_detail_data. */
+                device_interface_detail_data = (SP_DEVICE_INTERFACE_DETAIL_DATA_A*) malloc(required_size);

[Will Harris, 2014/01/14 23:40:01]

check return value of malloc

+                device_interface_detail_data->cbSize = sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA_A);
+
+                /* Get the detailed data for this device. The detail data gives us
+                   the device path for this device, which is then passed into
+                   CreateFile() to get a handle to the device. */
+                res = SetupDiGetDeviceInterfaceDetailA(device_info_set,
+                        &device_interface_data,
+                        device_interface_detail_data,
+                        required_size,
+                        NULL,
+                        NULL);
+
+                if (!res) {
+                        /* register_error(dev, "Unable to call SetupDiGetDeviceInterfaceDetail");
+                           Continue to the next device. */
+                        goto cont;
+                }
+
+                /* Make sure this device is of Setup Class "HIDClass" and has a
+                   driver bound to it. */
+                for (i = 0; ; i++) {
+                        char driver_name[256];

[Will Harris, 2014/01/14 23:40:01]

where is 256 from?

+
+                        /* Populate devinfo_data. This function will return failure
+                           when there are no more interfaces left. */
+                        res = SetupDiEnumDeviceInfo(device_info_set, i, &devinfo_data);
+                        if (!res)
+                                goto cont;
+
+                        res = SetupDiGetDeviceRegistryPropertyA(device_info_set, &devinfo_data,
+                                       SPDRP_CLASS, NULL, (PBYTE)driver_name, sizeof(driver_name), NULL);
+                        if (!res)
+                                goto cont;
+
+                        if (strcmp(driver_name, "HIDClass") == 0) {
+                                /* See if there's a driver bound. */
+                                res = SetupDiGetDeviceRegistryPropertyA(device_info_set, &devinfo_data,
+                                           SPDRP_DRIVER, NULL, (PBYTE)driver_name, sizeof(driver_name), NULL);
+                                if (res)
+                                        break;
+                        }
+                }
+
+                //wprintf(L"HandleName: %s\n", device_interface_detail_data->DevicePath);
+
+                /* Open a handle to the device */
+                write_handle = open_device(device_interface_detail_data->DevicePath, TRUE);
+
+                /* Check validity of write_handle. */
+                if (write_handle == INVALID_HANDLE_VALUE) {
+                        /* Unable to open the device. */
+                        //register_error(dev, "CreateFile");
+                        goto cont_close;

[Will Harris, 2014/01/14 23:40:01]

CloseHandle() on invalid handle later on

+                }               
+
+
+                /* Get the Vendor ID and Product ID for this device. */
+                attrib.Size = sizeof(HIDD_ATTRIBUTES);
+                HidD_GetAttributes(write_handle, &attrib);
+                //wprintf(L"Product/Vendor: %x %x\n", attrib.ProductID, attrib.VendorID);
+
+                /* Check the VID/PID to see if we should add this
+                   device to the enumeration list. */
+                if ((vendor_id == 0x0 || attrib.VendorID == vendor_id) &&
+                    (product_id == 0x0 || attrib.ProductID == product_id)) {
+
+                        #define WSTR_LEN 512
+                        const char *str;
+                        struct hid_device_info *tmp;
+                        PHIDP_PREPARSED_DATA pp_data = NULL;
+                        HIDP_CAPS caps;
+                        BOOLEAN res;
+                        NTSTATUS nt_res;
+                        wchar_t wstr[WSTR_LEN]; /* TODO: Determine Size */

[Will Harris, 2014/01/14 23:40:01]

seems like a rather scary TODO

+                        size_t len;
+
+                        /* VID/PID match. Create the record. */
+                        tmp = (struct hid_device_info*) calloc(1, sizeof(struct hid_device_info));
+                        if (cur_dev) {
+                                cur_dev->next = tmp;
+                        }
+                        else {
+                                root = tmp;
+                        }
+                        cur_dev = tmp;
+
+                        /* Get the Usage Page and Usage for this device. */
+                        res = HidD_GetPreparsedData(write_handle, &pp_data);
+                        if (res) {
+                                nt_res = HidP_GetCaps(pp_data, &caps);
+                                if (nt_res == HIDP_STATUS_SUCCESS) {
+                                        cur_dev->usage_page = caps.UsagePage;
+                                        cur_dev->usage = caps.Usage;
+                                }
+
+                                HidD_FreePreparsedData(pp_data);
+                        }
+                        
+                        /* Fill out the record */
+                        cur_dev->next = NULL;
+                        str = device_interface_detail_data->DevicePath;
+                        if (str) {
+                                len = strlen(str);
+                                cur_dev->path = (char*) calloc(len+1, sizeof(char));
+                                strncpy(cur_dev->path, str, len+1);
+                                cur_dev->path[len] = '\0';
+                        }
+                        else
+                                cur_dev->path = NULL;
+
+                        /* Serial Number */
+                        res = HidD_GetSerialNumberString(write_handle, wstr, sizeof(wstr));

[Will Harris, 2014/01/14 23:40:01]

these functions all take number of bytes but sizeof() is giving number of wchars

+                        wstr[WSTR_LEN-1] = 0x0000;
+                        if (res) {
+                                cur_dev->serial_number = _wcsdup(wstr);
+                        }
+
+                        /* Manufacturer String */
+                        res = HidD_GetManufacturerString(write_handle, wstr, sizeof(wstr));
+                        wstr[WSTR_LEN-1] = 0x0000;
+                        if (res) {
+                                cur_dev->manufacturer_string = _wcsdup(wstr);
+                        }
+
+                        /* Product String */
+                        res = HidD_GetProductString(write_handle, wstr, sizeof(wstr));
+                        wstr[WSTR_LEN-1] = 0x0000;
+                        if (res) {
+                                cur_dev->product_string = _wcsdup(wstr);
+                        }
+
+                        /* VID/PID */
+                        cur_dev->vendor_id = attrib.VendorID;
+                        cur_dev->product_id = attrib.ProductID;
+
+                        /* Release Number */
+                        cur_dev->release_number = attrib.VersionNumber;
+
+                        /* Interface Number. It can sometimes be parsed out of the path
+                           on Windows if a device has multiple interfaces. See
+                           http://msdn.microsoft.com/en-us/windows/hardware/gg487473 or
+                           search for "Hardware IDs for HID Devices" at MSDN. If it's not
+                           in the path, it's set to -1. */
+                        cur_dev->interface_number = -1;
+                        if (cur_dev->path) {
+                                char *interface_component = strstr(cur_dev->path, "&mi_");
+                                if (interface_component) {
+                                        char *hex_str = interface_component + 4;
+                                        char *endptr = NULL;
+                                        cur_dev->interface_number = strtol(hex_str, &endptr, 16);
+                                        if (endptr == hex_str) {
+                                                /* The parsing failed. Set interface_number to -1. */
+                                                cur_dev->interface_number = -1;
+                                        }
+                                }
+                        }
+                }
+
+cont_close:
+                CloseHandle(write_handle);
+cont:
+                /* We no longer need the detail data. It can be freed */
+                free(device_interface_detail_data);
+
+                device_index++;
+
+        }
+
+        /* Close the device information handle. */
+        SetupDiDestroyDeviceInfoList(device_info_set);
+
+        return root;
+
+}
+
+void  HID_API_EXPORT HID_API_CALL hid_free_enumeration(struct hid_device_info *devs)
+{
+        /* TODO: Merge this with the Linux version. This function is platform-independent. */
+        struct hid_device_info *d = devs;
+        while (d) {
+                struct hid_device_info *next = d->next;
+                free(d->path);
+                free(d->serial_number);
+                free(d->manufacturer_string);
+                free(d->product_string);
+                free(d);
+                d = next;
+        }
+}
+
+
+HID_API_EXPORT hid_device * HID_API_CALL hid_open(unsigned short vendor_id, unsigned short product_id, const wchar_t *serial_number)
+{
+        /* TODO: Merge this functions with the Linux version. This function should be platform independent. */
+        struct hid_device_info *devs, *cur_dev;
+        const char *path_to_open = NULL;
+        hid_device *handle = NULL;
+        
+        devs = hid_enumerate(vendor_id, product_id);
+        cur_dev = devs;
+        while (cur_dev) {
+                if (cur_dev->vendor_id == vendor_id &&
+                    cur_dev->product_id == product_id) {
+                        if (serial_number) {
+                                if (wcscmp(serial_number, cur_dev->serial_number) == 0) {
+                                        path_to_open = cur_dev->path;
+                                        break;
+                                }
+                        }
+                        else {
+                                path_to_open = cur_dev->path;
+                                break;
+                        }
+                }
+                cur_dev = cur_dev->next;
+        }
+
+        if (path_to_open) {
+                /* Open the device */
+                handle = hid_open_path(path_to_open);
+        }
+
+        hid_free_enumeration(devs);
+        
+        return handle;
+}
+
+HID_API_EXPORT hid_device * HID_API_CALL hid_open_path(const char *path)
+{
+        hid_device *dev;
+        HIDP_CAPS caps;
+        PHIDP_PREPARSED_DATA pp_data = NULL;
+        BOOLEAN res;
+        NTSTATUS nt_res;
+
+        if (hid_init() < 0) {
+                return NULL;
+        }
+
+        dev = new_hid_device();
+
+        /* Open a handle to the device */
+        dev->device_handle = open_device(path, FALSE);
+
+        /* Check validity of write_handle. */
+        if (dev->device_handle == INVALID_HANDLE_VALUE) {
+                /* Unable to open the device. */
+                register_error(dev, "CreateFile");
+                goto err;
+        }
+
+        /* Get the Input Report length for the device. */
+        res = HidD_GetPreparsedData(dev->device_handle, &pp_data);
+        if (!res) {
+                register_error(dev, "HidD_GetPreparsedData");
+                goto err;
+        }
+        nt_res = HidP_GetCaps(pp_data, &caps);
+        if (nt_res != HIDP_STATUS_SUCCESS) {
+                register_error(dev, "HidP_GetCaps");    
+                goto err_pp_data;
+        }
+        dev->output_report_length = caps.OutputReportByteLength;
+        dev->input_report_length = caps.InputReportByteLength;
+        HidD_FreePreparsedData(pp_data);
+
+        dev->read_buf = (char*) malloc(dev->input_report_length);

[Will Harris, 2014/01/14 23:40:01]

check return value

+
+        return dev;
+
+err_pp_data:
+                HidD_FreePreparsedData(pp_data);
+err:    
+                free_hid_device(dev);
+                return NULL;
+}
+
+int HID_API_EXPORT HID_API_CALL hid_write(hid_device *dev, const unsigned char *data, size_t length)
+{
+        DWORD bytes_written;
+        BOOL res;
+
+        OVERLAPPED ol;
+        unsigned char *buf;
+        memset(&ol, 0, sizeof(ol));
+
+        /* Make sure the right number of bytes are passed to WriteFile. Windows
+           expects the number of bytes which are in the _longest_ report (plus
+           one for the report number) bytes even if the data is a report
+           which is shorter than that. Windows gives us this value in
+           caps.OutputReportByteLength. If a user passes in fewer bytes than this,
+           create a temporary buffer which is the proper size. */
+        if (length >= dev->output_report_length) {
+                /* The user passed the right number of bytes. Use the buffer as-is. */
+                buf = (unsigned char *) data;
+        } else {
+                /* Create a temporary buffer and copy the user's data
+                   into it, padding the rest with zeros. */
+                buf = (unsigned char *) malloc(dev->output_report_length);
+                memcpy(buf, data, length);
+                memset(buf + length, 0, dev->output_report_length - length);
+                length = dev->output_report_length;
+        }
+
+        res = WriteFile(dev->device_handle, buf, length, NULL, &ol);
+        
+        if (!res) {
+                if (GetLastError() != ERROR_IO_PENDING) {
+                        /* WriteFile() failed. Return error. */
+                        register_error(dev, "WriteFile");
+                        bytes_written = -1;
+                        goto end_of_function;
+                }
+        }
+
+        /* Wait here until the write is done. This makes
+           hid_write() synchronous. */
+        res = GetOverlappedResult(dev->device_handle, &ol, &bytes_written, TRUE/*wait*/);
+        if (!res) {
+                /* The Write operation failed. */
+                register_error(dev, "WriteFile");
+                bytes_written = -1;
+                goto end_of_function;
+        }
+
+end_of_function:
+        if (buf != data)
+                free(buf);
+
+        return bytes_written;
+}
+
+
+int HID_API_EXPORT HID_API_CALL hid_read_timeout(hid_device *dev, unsigned char *data, size_t length, int milliseconds)
+{
+        DWORD bytes_read = 0;
+        BOOL res;
+
+        /* Copy the handle for convenience. */
+        HANDLE ev = dev->ol.hEvent;
+
+        if (!dev->read_pending) {
+                /* Start an Overlapped I/O read. */
+                dev->read_pending = TRUE;
+                memset(dev->read_buf, 0, dev->input_report_length);
+                ResetEvent(ev);
+                res = ReadFile(dev->device_handle, dev->read_buf, dev->input_report_length, &bytes_read, &dev->ol);
+                
+                if (!res) {
+                        if (GetLastError() != ERROR_IO_PENDING) {
+                                /* ReadFile() has failed.
+                                   Clean up and return error. */
+                                CancelIo(dev->device_handle);
+                                dev->read_pending = FALSE;
+                                goto end_of_function;
+                        }
+                }
+        }
+
+        if (milliseconds >= 0) {
+                /* See if there is any data yet. */
+                res = WaitForSingleObject(ev, milliseconds);
+                if (res != WAIT_OBJECT_0) {
+                        /* There was no data this time. Return zero bytes available,
+                           but leave the Overlapped I/O running. */
+                        return 0;
+                }
+        }
+
+        /* Either WaitForSingleObject() told us that ReadFile has completed, or
+           we are in non-blocking mode. Get the number of bytes read. The actual
+           data has been copied to the data[] array which was passed to ReadFile(). */
+        res = GetOverlappedResult(dev->device_handle, &dev->ol, &bytes_read, TRUE/*wait*/);
+        
+        /* Set pending back to false, even if GetOverlappedResult() returned error. */
+        dev->read_pending = FALSE;
+
+        if (res && bytes_read > 0) {
+                if (dev->read_buf[0] == 0x0) {
+                        /* If report numbers aren't being used, but Windows sticks a report
+                           number (0x0) on the beginning of the report anyway. To make this
+                           work like the other platforms, and to make it work more like the
+                           HID spec, we'll skip over this byte. */
+                        size_t copy_len;
+                        bytes_read--;
+                        copy_len = length > bytes_read ? bytes_read : length;
+                        memcpy(data, dev->read_buf+1, copy_len);
+                }
+                else {
+                        /* Copy the whole buffer, report number and all. */
+                        size_t copy_len = length > bytes_read ? bytes_read : length;
+                        memcpy(data, dev->read_buf, copy_len);
+                }
+        }
+        
+end_of_function:
+        if (!res) {
+                register_error(dev, "GetOverlappedResult");
+                return -1;
+        }
+        
+        return bytes_read;
+}
+
+int HID_API_EXPORT HID_API_CALL hid_read(hid_device *dev, unsigned char *data, size_t length)

[Will Harris, 2014/01/14 23:40:01]

your calls from Chromeland are using the blocking version, have you considered
using the non-blocking version instead?

+{
+        return hid_read_timeout(dev, data, length, (dev->blocking)? -1: 0);
+}
+
+int HID_API_EXPORT HID_API_CALL hid_set_nonblocking(hid_device *dev, int nonblock)
+{
+        dev->blocking = !nonblock;
+        return 0; /* Success */
+}
+
+int HID_API_EXPORT HID_API_CALL hid_send_feature_report(hid_device *dev, const unsigned char *data, size_t length)
+{
+        BOOL res = HidD_SetFeature(dev->device_handle, (PVOID)data, length);
+        if (!res) {
+                register_error(dev, "HidD_SetFeature");
+                return -1;
+        }
+
+        return length;
+}
+
+
+int HID_API_EXPORT HID_API_CALL hid_get_feature_report(hid_device *dev, unsigned char *data, size_t length)
+{
+        BOOL res;
+#if 0
+        res = HidD_GetFeature(dev->device_handle, data, length);
+        if (!res) {
+                register_error(dev, "HidD_GetFeature");
+                return -1;
+        }
+        return 0; /* HidD_GetFeature() doesn't give us an actual length, unfortunately */
+#else
+        DWORD bytes_returned;
+
+        OVERLAPPED ol;
+        memset(&ol, 0, sizeof(ol));
+
+        res = DeviceIoControl(dev->device_handle,
+                IOCTL_HID_GET_FEATURE,
+                data, length,
+                data, length,
+                &bytes_returned, &ol);
+
+        if (!res) {
+                if (GetLastError() != ERROR_IO_PENDING) {
+                        /* DeviceIoControl() failed. Return error. */
+                        register_error(dev, "Send Feature Report DeviceIoControl");
+                        return -1;
+                }
+        }
+
+        /* Wait here until the write is done. This makes
+           hid_get_feature_report() synchronous. */
+        res = GetOverlappedResult(dev->device_handle, &ol, &bytes_returned, TRUE/*wait*/);
+        if (!res) {
+                /* The operation failed. */
+                register_error(dev, "Send Feature Report GetOverLappedResult");
+                return -1;
+        }
+        return bytes_returned;
+#endif
+}
+
+void HID_API_EXPORT HID_API_CALL hid_close(hid_device *dev)
+{
+        if (!dev)
+                return;
+        CancelIo(dev->device_handle);
+        free_hid_device(dev);
+}
+
+int HID_API_EXPORT_CALL HID_API_CALL hid_get_manufacturer_string(hid_device *dev, wchar_t *string, size_t maxlen)
+{
+        BOOL res;
+
+        res = HidD_GetManufacturerString(dev->device_handle, string, sizeof(wchar_t) * maxlen);
+        if (!res) {
+                register_error(dev, "HidD_GetManufacturerString");
+                return -1;
+        }
+
+        return 0;
+}
+
+int HID_API_EXPORT_CALL HID_API_CALL hid_get_product_string(hid_device *dev, wchar_t *string, size_t maxlen)
+{
+        BOOL res;
+
+        res = HidD_GetProductString(dev->device_handle, string, sizeof(wchar_t) * maxlen);
+        if (!res) {
+                register_error(dev, "HidD_GetProductString");
+                return -1;
+        }
+
+        return 0;
+}
+
+int HID_API_EXPORT_CALL HID_API_CALL hid_get_serial_number_string(hid_device *dev, wchar_t *string, size_t maxlen)
+{
+        BOOL res;
+
+        res = HidD_GetSerialNumberString(dev->device_handle, string, sizeof(wchar_t) * maxlen);
+        if (!res) {
+                register_error(dev, "HidD_GetSerialNumberString");
+                return -1;
+        }
+
+        return 0;
+}
+
+int HID_API_EXPORT_CALL HID_API_CALL hid_get_indexed_string(hid_device *dev, int string_index, wchar_t *string, size_t maxlen)
+{
+        BOOL res;
+
+        res = HidD_GetIndexedString(dev->device_handle, string_index, string, sizeof(wchar_t) * maxlen);
+        if (!res) {
+                register_error(dev, "HidD_GetIndexedString");
+                return -1;
+        }
+
+        return 0;
+}
+
+
+HID_API_EXPORT const wchar_t * HID_API_CALL  hid_error(hid_device *dev)
+{
+        return (wchar_t*)dev->last_error_str;
+}
+
+
+/*#define PICPGM*/
+/*#define S11*/
+#define P32
+#ifdef S11 
+  unsigned short VendorID = 0xa0a0;
+        unsigned short ProductID = 0x0001;
+#endif
+
+#ifdef P32
+  unsigned short VendorID = 0x04d8;
+        unsigned short ProductID = 0x3f;
+#endif
+
+
+#ifdef PICPGM
+  unsigned short VendorID = 0x04d8;
+  unsigned short ProductID = 0x0033;
+#endif
+
+
+#if 0
+int __cdecl main(int argc, char* argv[])

[Will Harris, 2014/01/14 23:40:01]

can this test code be removed and/or replaced with proper unit tests?

+{
+        int res;
+        unsigned char buf[65];
+
+        UNREFERENCED_PARAMETER(argc);
+        UNREFERENCED_PARAMETER(argv);
+
+        /* Set up the command buffer. */
+        memset(buf,0x00,sizeof(buf));
+        buf[0] = 0;
+        buf[1] = 0x81;
+        
+
+        /* Open the device. */
+        int handle = open(VendorID, ProductID, L"12345");
+        if (handle < 0)
+                printf("unable to open device\n");
+
+
+        /* Toggle LED (cmd 0x80) */
+        buf[1] = 0x80;
+        res = write(handle, buf, 65);
+        if (res < 0)
+                printf("Unable to write()\n");
+
+        /* Request state (cmd 0x81) */
+        buf[1] = 0x81;
+        write(handle, buf, 65);
+        if (res < 0)
+                printf("Unable to write() (2)\n");
+
+        /* Read requested state */
+        read(handle, buf, 65);
+        if (res < 0)
+                printf("Unable to read()\n");
+
+        /* Print out the returned buffer. */
+        for (int i = 0; i < 4; i++)
+                printf("buf[%d]: %d\n", i, buf[i]);
+
+        return 0;
+}
+#endif
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif