Make nonblock available again for file inputs

2 files changed, 159 insertions, 103 deletions

diff --git a/src/input/File.cpp b/src/input/File.cpp
index 5c61fd4..54dac1e 100644
--- a/src/input/File.cpp
+++ b/src/input/File.cpp
@@ -2,7 +2,7 @@
    Copyright (C) 2009 Her Majesty the Queen in Right of Canada (Communications
    Research Center Canada)
 
-   Copyright (C) 2016 Matthias P. Braendli
+   Copyright (C) 2018 Matthias P. Braendli
     http://www.opendigitalradio.org
 
    */
@@ -23,16 +23,14 @@
    along with ODR-DabMux.  If not, see <http://www.gnu.org/licenses/>.
    */
 
-#include <sstream>
 #include <errno.h>
-#include <stdlib.h>
-#include <stdio.h>
+#include <cstdlib>
+#include <cstdio>
 #include <fcntl.h>
 #include <unistd.h>
 #ifndef _WIN32
 #   define O_BINARY 0
 #endif
-
 #include "input/File.h"
 #include "mpeg.h"
 #include "ReedSolomon.h"
@@ -62,12 +60,15 @@ __attribute((packed))
 
 int FileBase::open(const std::string& name)
 {
-    m_fd = ::open(name.c_str(), O_RDONLY | O_BINARY);
+    int flags = O_RDONLY | O_BINARY;
+    if (m_nonblock) {
+        flags |= O_NONBLOCK;
+    }
+
+    m_fd = ::open(name.c_str(), flags);
     if (m_fd == -1) {
-        std::stringstream ss;
-        ss << "Could not open input file " << name << ": " <<
-            strerror(errno);
-        throw std::runtime_error(ss.str());
+        throw std::runtime_error("Could not open input file " + name + ": " +
+            strerror(errno));
     }
     return 0;
 }
@@ -75,7 +76,7 @@ int FileBase::open(const std::string& name)
 int FileBase::setBitrate(int bitrate)
 {
     if (bitrate <= 0) {
-        etiLog.log(error, "Invalid bitrate (%i)\n", bitrate);
+        etiLog.log(error, "Invalid bitrate (%i)", bitrate);
         return -1;
     }
 
@@ -92,6 +93,11 @@ int FileBase::close()
     return 0;
 }
 
+void FileBase::setNonblocking(bool nonblock)
+{
+    m_nonblock = nonblock;
+}
+
 int FileBase::rewind()
 {
     return ::lseek(m_fd, 0, SEEK_SET);
@@ -99,32 +105,78 @@ int FileBase::rewind()
 
 ssize_t FileBase::readFromFile(uint8_t* buffer, size_t size)
 {
-    ssize_t ret = read(m_fd, buffer, size);
+    ssize_t ret = 0;
+    if (m_nonblock) {
+        if (size > m_nonblock_buffer.size()) {
+            size_t required_len = size - m_nonblock_buffer.size();
+            std::vector<uint8_t> buf(required_len);
+            ret = read(m_fd, buf.data(), required_len);
+
+            /* If no process has the pipe open for writing, read() shall return 0
+             * to indicate end-of-file. */
+            if (ret == 0) {
+                return 0;
+            }
 
-    if (ret == -1) {
-        etiLog.log(alert, "ERROR: Can't read file\n");
-        perror("");
-        return -1;
-    }
+            /* If some process has the pipe open for writing and O_NONBLOCK is
+             * set, read() shall return −1 and set errno to [EAGAIN]. */
+            if (ret == -1 and errno == EAGAIN) {
+                return 0;
+            }
+            else if (ret == -1) {
+                etiLog.level(alert) << "ERROR: Can't read file " << strerror(errno);
+                return -1;
+            }
 
-    if (ret < (ssize_t)size) {
-        ssize_t sizeOut = ret;
-        etiLog.log(info, "reach end of file -> rewinding\n");
-        if (rewind() == -1) {
-            etiLog.log(alert, "ERROR: Can't rewind file\n");
-            return -1;
+            if (buf.size() + ret == size) {
+                std::copy(m_nonblock_buffer.begin(), m_nonblock_buffer.end(),
+                        buffer);
+                buffer += m_nonblock_buffer.size();
+                m_nonblock_buffer.clear();
+                std::copy(buf.begin(), buf.end(), buffer);
+                return size;
+            }
         }
+        else {
+            std::copy(m_nonblock_buffer.begin(), m_nonblock_buffer.begin() + size,
+                    buffer);
+
+            std::vector<uint8_t> remaining_buf;
+            std::copy(m_nonblock_buffer.begin() + size, m_nonblock_buffer.end(),
+                    std::back_inserter(remaining_buf));
+
+            m_nonblock_buffer = std::move(remaining_buf);
+            return size;
+        }
+        return 0;
+    }
+    else {
+        ret = read(m_fd, buffer, size);
 
-        ret = read(m_fd, buffer + sizeOut, size - sizeOut);
         if (ret == -1) {
-            etiLog.log(alert, "ERROR: Can't read file\n");
-            perror("");
+            etiLog.level(alert) << "ERROR: Can't read file " << strerror(errno);
             return -1;
         }
 
         if (ret < (ssize_t)size) {
-            etiLog.log(alert, "ERROR: Not enough data in file\n");
-            return -1;
+            ssize_t sizeOut = ret;
+            etiLog.log(info, "reach end of file -> rewinding");
+            if (rewind() == -1) {
+                etiLog.log(alert, "ERROR: Can't rewind file");
+                return -1;
+            }
+
+            ret = read(m_fd, buffer + sizeOut, size - sizeOut);
+            if (ret == -1) {
+                etiLog.log(alert, "ERROR: Can't read file");
+                perror("");
+                return -1;
+            }
+
+            if (ret < (ssize_t)size) {
+                etiLog.log(alert, "ERROR: Not enough data in file");
+                return -1;
+            }
         }
     }
 
@@ -140,7 +192,8 @@ READ_SUBCHANNEL:
         result = readData(m_fd, buffer, size, 2);
         m_parity = false;
         return 0;
-    } else {
+    }
+    else {
         result = readMpegHeader(m_fd, buffer, size);
         if (result > 0) {
             result = readMpegFrame(m_fd, buffer, size);
@@ -151,79 +204,77 @@ READ_SUBCHANNEL:
         }
     }
     switch (result) {
-    case MPEG_BUFFER_UNDERFLOW:
-        etiLog.log(warn, "data underflow -> frame muted\n");
-        goto MUTE_SUBCHANNEL;
-    case MPEG_BUFFER_OVERFLOW:
-        etiLog.log(warn, "bitrate too high -> frame muted\n");
-        goto MUTE_SUBCHANNEL;
-    case MPEG_FILE_EMPTY:
-        if (do_rewind) {
-            etiLog.log(error, "file rewinded and still empty "
-                    "-> frame muted\n");
+        case MPEG_BUFFER_UNDERFLOW:
+            etiLog.log(warn, "data underflow -> frame muted");
             goto MUTE_SUBCHANNEL;
-        }
-        else {
-            etiLog.log(info, "reach end of file -> rewinding\n");
-            rewind();
-            goto READ_SUBCHANNEL;
-        }
-    case MPEG_FILE_ERROR:
-        etiLog.log(alert, "can't read file (%i) -> frame muted\n", errno);
-        perror("");
-        goto MUTE_SUBCHANNEL;
-    case MPEG_SYNC_NOT_FOUND:
-        etiLog.log(alert, "mpeg sync not found, maybe is not a valid file "
-                "-> frame muted\n");
-        goto MUTE_SUBCHANNEL;
-    case MPEG_INVALID_FRAME:
-        etiLog.log(alert, "file is not a valid mpeg file "
-                "-> frame muted\n");
-        goto MUTE_SUBCHANNEL;
-    default:
-        if (result < 0) {
-            etiLog.log(alert,
-                    "unknown error (code = %i) -> frame muted\n",
-                    result);
+        case MPEG_BUFFER_OVERFLOW:
+            etiLog.log(warn, "bitrate too high -> frame muted");
+            goto MUTE_SUBCHANNEL;
+        case MPEG_FILE_EMPTY:
+            if (do_rewind) {
+                etiLog.log(error, "file rewinded and still empty "
+                        "-> frame muted");
+                goto MUTE_SUBCHANNEL;
+            }
+            else {
+                etiLog.log(info, "reach end of file -> rewinding");
+                rewind();
+                goto READ_SUBCHANNEL;
+            }
+        case MPEG_FILE_ERROR:
+            etiLog.log(alert, "can't read file (%i) -> frame muted", errno);
+            perror("");
+            goto MUTE_SUBCHANNEL;
+        case MPEG_SYNC_NOT_FOUND:
+            etiLog.log(alert, "mpeg sync not found, maybe is not a valid file "
+                    "-> frame muted");
+            goto MUTE_SUBCHANNEL;
+        case MPEG_INVALID_FRAME:
+            etiLog.log(alert, "file is not a valid mpeg file "
+                    "-> frame muted");
+            goto MUTE_SUBCHANNEL;
+        default:
+            if (result < 0) {
+                etiLog.log(alert,
+                        "unknown error (code = %i) -> frame muted",
+                        result);
 MUTE_SUBCHANNEL:
-            memset(buffer, 0, size);
-        }
-        else {
-            if (result < (ssize_t)size) {
-                etiLog.log(warn, "bitrate too low from file "
-                        "-> frame padded\n");
-                memset((char*)buffer + result, 0, size - result);
+                memset(buffer, 0, size);
             }
+            else {
+                if (result < (ssize_t)size) {
+                    etiLog.log(warn, "bitrate too low from file "
+                            "-> frame padded");
+                    memset((char*)buffer + result, 0, size - result);
+                }
 
-            result = checkDabMpegFrame(buffer);
-            switch (result) {
-            case MPEG_FREQUENCY:
-                etiLog.log(error, "file has a frame with an invalid "
-                        "frequency: %i, should be 48000 or 24000\n",
-                        getMpegFrequency(buffer));
-                break;
-            case MPEG_PADDING:
-                etiLog.log(warn,
-                        "file has a frame with padding bit set\n");
-                break;
-            case MPEG_COPYRIGHT:
-                result = 0;
-                break;
-            case MPEG_ORIGINAL:
-                result = 0;
-                break;
-            case MPEG_EMPHASIS:
-                etiLog.log(warn,
-                        "file has a frame with emphasis bits set\n");
-                break;
-            default:
-                if (result < 0) {
-                    etiLog.log(alert, "mpeg file has an invalid DAB "
-                            "mpeg frame (unknown reason: %i)\n", result);
+                result = checkDabMpegFrame(buffer);
+                switch (result) {
+                    case MPEG_FREQUENCY:
+                        etiLog.log(error, "file has a frame with an invalid "
+                                "frequency: %i, should be 48000 or 24000",
+                                getMpegFrequency(buffer));
+                        break;
+                    case MPEG_PADDING:
+                        etiLog.log(warn, "file has a frame with padding bit setn");
+                        break;
+                    case MPEG_COPYRIGHT:
+                        result = 0;
+                        break;
+                    case MPEG_ORIGINAL:
+                        result = 0;
+                        break;
+                    case MPEG_EMPHASIS:
+                        etiLog.log(warn, "file has a frame with emphasis bits set");
+                        break;
+                    default:
+                        if (result < 0) {
+                            etiLog.log(alert, "mpeg file has an invalid DAB "
+                                    "mpeg frame (unknown reason: %i)", result);
+                        }
+                        break;
                 }
-                break;
             }
-        }
     }
     return result;
 }
@@ -362,7 +413,7 @@ int PacketFile::readFrame(uint8_t* buffer, size_t size)
             else if (nbBytes < 3) {
                 etiLog.log(error,
                         "Error while reading file for packet header; "
-                        "read %i out of 3 bytes\n", nbBytes);
+                        "read %i out of 3 bytes", nbBytes);
                 break;
             }
 
@@ -390,7 +441,7 @@ int PacketFile::readFrame(uint8_t* buffer, size_t size)
             }
             else if (nbBytes == 0) {
                 etiLog.log(info,
-                        "Packet header read, but no data!\n");
+                        "Packet header read, but no data!");
                 if (rewind() == -1) {
                     goto END_PACKET;
                 }
@@ -398,7 +449,7 @@ int PacketFile::readFrame(uint8_t* buffer, size_t size)
             }
             else if (nbBytes < length - 3) {
                 etiLog.log(error, "Error while reading packet file; "
-                        "read %i out of %i bytes\n", nbBytes, length - 3);
+                        "read %i out of %i bytes", nbBytes, length - 3);
                 break;
             }
 
@@ -416,7 +467,7 @@ int PacketFile::readFrame(uint8_t* buffer, size_t size)
                 if (m_enhancedPacketLength >= (12 * 188)) {
                     if (m_enhancedPacketLength > (12 * 188)) {
                         etiLog.log(error,
-                                "Error, too much enhanced packet data!\n");
+                                "Error, too much enhanced packet data!");
                     }
                     ReedSolomon encoder(204, 188);
                     for (int j = 0; j < 12; ++j) {
diff --git a/src/input/File.h b/src/input/File.h
index 080d6b5..62a6707 100644
--- a/src/input/File.h
+++ b/src/input/File.h
@@ -2,7 +2,7 @@
    Copyright (C) 2009 Her Majesty the Queen in Right of Canada (Communications
    Research Center Canada)
 
-   Copyright (C) 2016 Matthias P. Braendli
+   Copyright (C) 2018 Matthias P. Braendli
     http://www.opendigitalradio.org
 
    */
@@ -28,7 +28,7 @@
 #include <vector>
 #include <array>
 #include <string>
-#include <stdint.h>
+#include <cstdint>
 #include "input/inputs.h"
 #include "ManagementServer.h"
 
@@ -41,6 +41,8 @@ class FileBase : public InputBase {
         virtual int setBitrate(int bitrate);
         virtual int close();
 
+        virtual void setNonblocking(bool nonblock);
+
         /* Rewind the file
          * Returns -1 on failure, 0 on success
          */
@@ -52,8 +54,11 @@ class FileBase : public InputBase {
         virtual ssize_t readFromFile(uint8_t* buf, size_t len);
 
         // We use unix open() instead of fopen() because
-        // we might want to do non-blocking I/O in the future
+        // of non-blocking I/O
         int m_fd = -1;
+
+        bool m_nonblock = false;
+        std::vector<uint8_t> m_nonblock_buffer;
 };
 
 class MPEGFile : public FileBase {