Add creeate, put and delete support to the CP/M filesystem driver.

lib/vfs/cpmfs.cc

@@ -1,19 +1,24 @@
 #include "lib/globals.h"
 #include "lib/vfs/vfs.h"
 #include "lib/config.pb.h"
+#include <fmt/format.h>
+#include <regex>
 
-class CpmFsFilesystem : public Filesystem
+class CpmFsFilesystem : public Filesystem, public HasBitmap, public HasMount
 {
     class Entry
     {
     public:
-        Entry(const Bytes& bytes, int map_entry_size)
+        Entry(const Bytes& bytes, int map_entry_size, unsigned index):
+            index(index)
         {
+            if (bytes[0] == 0xe5)
+                deleted = true;
+
             user = bytes[0] & 0x0f;
 
             {
                 std::stringstream ss;
-                ss << (char)(user + '0') << ':';
 
                 for (int i = 1; i <= 8; i++)
                 {
@@ -64,13 +69,117 @@ class CpmFsFilesystem : public Filesystem
             }
         }
 
+        Bytes toBytes(int map_entry_size) const
+        {
+            Bytes bytes(32);
+            ByteWriter bw(bytes);
+
+            if (deleted)
+            {
+                for (int i = 0; i < 32; i++)
+                    bw.write_8(0xe5);
+            }
+            else
+            {
+                bw.write_8(user);
+
+                /* Encode the filename. */
+
+                for (int i = 1; i < 12; i++)
+                    bytes[i] = 0x20;
+                for (char c : filename)
+                {
+                    if (islower(c))
+                        throw BadPathException();
+                    if (c == '.')
+                    {
+                        if (bw.pos >= 9)
+                            throw BadPathException();
+                        bw.seek(9);
+                        continue;
+                    }
+                    if ((bw.pos == 9) || (bw.pos == 12))
+                        throw BadPathException();
+                    bw.write_8(c);
+                }
+
+                /* Set the mode. */
+
+                if (mode.find('R') != std::string::npos)
+                    bytes[9] |= 0x80;
+                if (mode.find('S') != std::string::npos)
+                    bytes[10] |= 0x80;
+                if (mode.find('A') != std::string::npos)
+                    bytes[11] |= 0x80;
+
+                /* EX, S1, S2, RC */
+
+                bw.seek(12);
+                bw.write_8(extent & 0x1f); /* EX */
+                bw.write_8(0);             /* S1 */
+                bw.write_8(extent >> 5);   /* S2 */
+                bw.write_8(records);       /* RC */
+
+                /* Allocation map. */
+
+                switch (map_entry_size)
+                {
+                    case 1:
+                        for (int i = 0; i < 16; i++)
+                            bw.write_8(allocation_map[i]);
+                        break;
+
+                    case 2:
+                        for (int i = 0; i < 8; i++)
+                            bw.write_le16(allocation_map[i]);
+                        break;
+                }
+            }
+
+            return bytes;
+        }
+
+        void changeFilename(const std::string& filename)
+        {
+            static std::regex FORMATTER("(?:(1?[0-9]):)?([^ .]+)\\.?([^ .]*)");
+            std::smatch results;
+            bool matched = std::regex_match(filename, results, FORMATTER);
+            if (!matched)
+                throw BadPathException();
+
+            std::string user = results[1];
+            std::string stem = results[2];
+            std::string ext = results[3];
+
+            if (stem.size() > 8)
+                throw BadPathException();
+            if (ext.size() > 3)
+                throw BadPathException();
+
+            this->user = std::stoi(user);
+            if (this->user > 15)
+                throw BadPathException();
+
+            if (ext.empty())
+                this->filename = stem;
+            else
+                this->filename = fmt::format("{}.{}", stem, ext);
+        }
+
+        std::string combinedFilename() const
+        {
+            return fmt::format("{}:{}", user, filename);
+        }
+
     public:
+        unsigned index;
         std::string filename;
         std::string mode;
         unsigned user;
         unsigned extent;
         unsigned records;
         std::vector<unsigned> allocation_map;
+        bool deleted = false;
     };
 
 public:
@@ -83,7 +192,8 @@ public:
 
     uint32_t capabilities() const override
     {
-        return OP_GETFSDATA | OP_LIST | OP_GETFILE | OP_GETDIRENT;
+        return OP_GETFSDATA | OP_LIST | OP_GETFILE | OP_PUTFILE | OP_DELETE |
+               OP_GETDIRENT | OP_CREATE;
     }
 
     std::map<std::string, std::string> getMetadata() override
@@ -94,7 +204,7 @@ public:
         for (int d = 0; d < _config.dir_entries(); d++)
         {
             auto entry = getEntry(d);
-            if (!entry)
+            if (entry->deleted)
                 continue;
 
             for (unsigned block : entry->allocation_map)
@@ -112,6 +222,17 @@ public:
         return attributes;
     }
 
+    void create(bool, const std::string&) override
+    {
+        auto& start = _config.filesystem_start();
+        _filesystemStart =
+            getOffsetOfSector(start.track(), start.side(), start.sector());
+        _sectorSize = getLogicalSectorSize(start.track(), start.side());
+
+        _directory = Bytes{0xe5} * (_config.dir_entries() * 32);
+        putCpmBlock(0, _directory);
+    }
+
     FilesystemStatus check() override
     {
         return FS_OK;
@@ -127,15 +248,15 @@ public:
         for (int d = 0; d < _config.dir_entries(); d++)
         {
             auto entry = getEntry(d);
-            if (!entry)
+            if (entry->deleted)
                 continue;
 
-            auto& dirent = map[entry->filename];
+            auto& dirent = map[entry->combinedFilename()];
             if (!dirent)
             {
                 dirent = std::make_unique<Dirent>();
-                dirent->path = {entry->filename};
-                dirent->filename = entry->filename;
+                dirent->filename = entry->combinedFilename();
+                dirent->path = {dirent->filename};
                 dirent->mode = entry->mode;
                 dirent->length = 0;
                 dirent->file_type = TYPE_FILE;
@@ -190,9 +311,9 @@ public:
             for (int d = 0; d < _config.dir_entries(); d++)
             {
                 entry = getEntry(d);
-                if (!entry)
+                if (entry->deleted)
                     continue;
-                if (path[0] != entry->filename)
+                if (path[0] != entry->combinedFilename())
                     continue;
                 if (entry->extent < logicalExtent)
                     continue;
@@ -201,7 +322,7 @@ public:
                     break;
             }
 
-            if (!entry)
+            if (entry->deleted)
             {
                 if (logicalExtent == 0)
                     throw FileNotFoundException();
@@ -236,8 +357,116 @@ public:
         return data;
     }
 
-private:
-    void mount()
+public:
+    void putFile(const Path& path, const Bytes& bytes) override
+    {
+        mount();
+        if (path.size() != 1)
+            throw BadPathException();
+
+        /* Test to see if the file already exists. */
+
+        for (int d = 0; d < _config.dir_entries(); d++)
+        {
+            std::unique_ptr<Entry> entry = getEntry(d);
+            if (entry->deleted)
+                continue;
+            if (path[0] == entry->combinedFilename())
+                throw CannotWriteException();
+        }
+
+        /* Write blocks, one at a time. */
+
+        std::unique_ptr<Entry> entry;
+        ByteReader br(bytes);
+        while (!br.eof())
+        {
+            unsigned extent = br.pos / 0x4000;
+            Bytes block = br.read(_config.block_size());
+
+            /* Allocate a block and write it. */
+
+            auto bit = std::find(_bitmap.begin(), _bitmap.end(), false);
+            if (bit == _bitmap.end())
+                throw DiskFullException();
+            *bit = true;
+            unsigned blocknum = bit - _bitmap.begin();
+            putCpmBlock(blocknum, block);
+
+            /* Do we need a new directory entry? */
+
+            if (!entry ||
+                entry->allocation_map[std::size(entry->allocation_map) - 1])
+            {
+                if (entry)
+                {
+                    entry->records = 0x80;
+                    putEntry(entry);
+                }
+
+                entry.reset();
+                for (int d = 0; d < _config.dir_entries(); d++)
+                {
+                    entry = getEntry(d);
+                    if (entry->deleted)
+                        break;
+                    entry.reset();
+                }
+
+                if (!entry)
+                    throw DiskFullException();
+                entry->deleted = false;
+                entry->changeFilename(path[0]);
+                entry->extent = extent;
+                entry->mode = "";
+                std::fill(entry->allocation_map.begin(),
+                    entry->allocation_map.end(),
+                    0);
+            }
+
+            /* Hook up the block in the allocation map. */
+
+            auto mit = std::find(
+                entry->allocation_map.begin(), entry->allocation_map.end(), 0);
+            *mit = blocknum;
+        }
+        if (entry)
+        {
+            entry->records = ((bytes.size() & 0x3fff) + 127) / 128;
+            putEntry(entry);
+        }
+
+        unmount();
+    }
+
+    void deleteFile(const Path& path) override
+    {
+        mount();
+        if (path.size() != 1)
+            throw BadPathException();
+
+        /* Remove all dirents for this file. */
+
+        bool found = false;
+        for (int d = 0; d < _config.dir_entries(); d++)
+        {
+            auto entry = getEntry(d);
+            if (entry->deleted)
+                continue;
+            if (path[0] != entry->combinedFilename())
+                continue;
+            entry->deleted = true;
+            putEntry(entry);
+            found = true;
+        }
+
+        if (!found)
+            throw FileNotFoundException();
+        unmount();
+    }
+
+public:
+    void mount() override
     {
         auto& start = _config.filesystem_start();
         _filesystemStart =
@@ -268,26 +497,71 @@ private:
         _blocksPerLogicalExtent = 16384 / _config.block_size();
 
         _directory = getCpmBlock(0, _dirBlocks);
+
+        /* Create the allocation bitmap. */
+
+        _bitmap.clear();
+        _bitmap.resize(_filesystemBlocks);
+        for (int d = 0; d < _dirBlocks; d++)
+            _bitmap[d] = true;
+        for (int d = 0; d < _config.dir_entries(); d++)
+        {
+            std::unique_ptr<Entry> entry = getEntry(d);
+            if (entry->deleted)
+                continue;
+            for (unsigned block : entry->allocation_map)
+            {
+                if (block >= _filesystemBlocks)
+                    throw BadFilesystemException();
+                if (block)
+                    _bitmap[block] = true;
+            }
+        }
     }
 
+    void unmount()
+    {
+        putCpmBlock(0, _directory);
+    }
+
+private:
     std::unique_ptr<Entry> getEntry(unsigned d)
     {
         auto bytes = _directory.slice(d * 32, 32);
-        if (bytes[0] == 0xe5)
-            return nullptr;
-
-        return std::make_unique<Entry>(bytes, _allocationMapSize);
+        return std::make_unique<Entry>(bytes, _allocationMapSize, d);
     }
 
-    Bytes getCpmBlock(uint32_t number, uint32_t count = 1)
+    void putEntry(std::unique_ptr<Entry>& entry)
     {
-        unsigned sector = number * _blockSectors;
+        ByteWriter bw(_directory);
+        bw.seek(entry->index * 32);
+        bw.append(entry->toBytes(_allocationMapSize));
+    }
+
+    unsigned computeSector(uint32_t block) const
+    {
+        unsigned sector = block * _blockSectors;
         if (_config.has_padding())
             sector += (sector / _config.padding().every()) *
                       _config.padding().amount();
+        return sector;
+    }
 
+    Bytes getCpmBlock(uint32_t block, uint32_t count = 1)
+    {
         return getLogicalSector(
-            sector + _filesystemStart, _blockSectors * count);
+            computeSector(block) + _filesystemStart, _blockSectors * count);
+    }
+
+    void putCpmBlock(uint32_t block, const Bytes& bytes)
+    {
+        putLogicalSector(computeSector(block) + _filesystemStart, bytes);
+    }
+
+public:
+    std::vector<bool> getBitmapForDebugging() override
+    {
+        return _bitmap;
     }
 
 private:
@@ -303,6 +577,7 @@ private:
     uint32_t _blocksPerLogicalExtent;
     int _allocationMapSize;
     Bytes _directory;
+    std::vector<bool> _bitmap;
 };
 
 std::unique_ptr<Filesystem> Filesystem::createCpmFsFilesystem(

lib/vfs/vfs.h

@@ -277,4 +277,18 @@ public:
     static std::unique_ptr<Filesystem> createFilesystemFromConfig();
 };
 
+/* Used for tests only. */
+
+class HasBitmap
+{
+public:
+    virtual std::vector<bool> getBitmapForDebugging() = 0;
+};
+
+class HasMount
+{
+public:
+    virtual void mount() = 0;
+};
+
 #endif

tests/cpmfs.cc

@@ -37,14 +37,22 @@ namespace
     };
 }
 
+static std::ostream& operator<<(std::ostream& stream, const Bytes& bytes)
+{
+    stream << '\n';
+    hexdump(stream, bytes);
+    return stream;
+}
+
 static Bytes createDirent(const std::string& filename,
     int extent,
     int records,
-    const std::initializer_list<int> blocks)
+    const std::initializer_list<int> blocks,
+    int user = 0)
 {
     Bytes dirent;
     ByteWriter bw(dirent);
-    bw.write_8(0);
+    bw.write_8(user);
     bw.append(filename);
     while (bw.pos != 12)
         bw.write_8(' ');
@@ -69,6 +77,21 @@ static void setBlock(
         sectors->put(block, 0, i)->data = data.slice(i * 256, 256);
 }
 
+static Bytes getBlock(
+    const std::shared_ptr<SectorInterface>& sectors, int block, int length)
+{
+    Bytes bytes;
+    ByteWriter bw(bytes);
+
+    for (int i = 0; i < (length + 127) / 128; i++)
+    {
+        auto sector = sectors->get(block, 0, i);
+        bw.append(sector->data);
+    }
+
+    return bytes;
+}
+
 static void testPartialExtent()
 {
     auto sectors = std::make_shared<TestSectorInterface>();
@@ -113,6 +136,93 @@ static void testLogicalExtents()
     AssertThat(data[0x4000 * 2], Equals(3));
 }
 
+static void testBitmap()
+{
+    auto sectors = std::make_shared<TestSectorInterface>();
+    auto fs = Filesystem::createCpmFsFilesystem(
+        globalConfig()->filesystem(), sectors);
+
+    setBlock(sectors,
+        0,
+        createDirent("FILE", 1, 128, {1, 0, 0, 0, 0, 0, 0, 0, 2}) +
+            createDirent("FILE", 2, 128, {4}) + (blank_dirent * 62));
+
+    dynamic_cast<HasMount*>(fs.get())->mount();
+    std::vector<bool> bitmap =
+        dynamic_cast<HasBitmap*>(fs.get())->getBitmapForDebugging();
+    AssertThat(bitmap,
+        Equals(std::vector<bool>{
+            1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}));
+}
+
+static void testPutGet()
+{
+    auto sectors = std::make_shared<TestSectorInterface>();
+    auto fs = Filesystem::createCpmFsFilesystem(
+        globalConfig()->filesystem(), sectors);
+    fs->create(true, "volume");
+
+    fs->putFile(Path("0:FILE1"), Bytes{1, 2, 3, 4});
+    fs->putFile(Path("0:FILE2"), Bytes{5, 6, 7, 8});
+
+    dynamic_cast<HasMount*>(fs.get())->mount();
+    std::vector<bool> bitmap =
+        dynamic_cast<HasBitmap*>(fs.get())->getBitmapForDebugging();
+    AssertThat(bitmap,
+        Equals(std::vector<bool>{
+            1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}));
+
+    auto directory = getBlock(sectors, 0, 256).slice(0, 64);
+    AssertThat(directory,
+        Equals(createDirent("FILE1", 0, 1, {1}) +
+               createDirent("FILE2", 0, 1, {2})));
+
+    auto file1 = getBlock(sectors, 1, 8).slice(0, 8);
+    AssertThat(file1, Equals(Bytes{1, 2, 3, 4, 0, 0, 0, 0}));
+
+    auto file2 = getBlock(sectors, 2, 8).slice(0, 8);
+    AssertThat(file2, Equals(Bytes{5, 6, 7, 8, 0, 0, 0, 0}));
+}
+
+static void testPutBigFile()
+{
+    auto sectors = std::make_shared<TestSectorInterface>();
+    auto fs = Filesystem::createCpmFsFilesystem(
+        globalConfig()->filesystem(), sectors);
+    fs->create(true, "volume");
+
+    Bytes filedata;
+    ByteWriter bw(filedata);
+    while (filedata.size() < 0x9000)
+        bw.write_le32(bw.pos);
+
+    fs->putFile(Path("0:BIGFILE"), filedata);
+
+    auto directory = getBlock(sectors, 0, 256).slice(0, 64);
+    AssertThat(directory,
+        Equals(createDirent("BIGFILE",
+                   0,
+                   0x80,
+                   {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}) +
+               createDirent("BIGFILE", 2, 0x20, {17, 18})));
+}
+
+static auto testDelete()
+{
+    auto sectors = std::make_shared<TestSectorInterface>();
+    auto fs = Filesystem::createCpmFsFilesystem(
+        globalConfig()->filesystem(), sectors);
+    fs->create(true, "volume");
+
+    fs->putFile(Path("0:FILE1"), Bytes{1, 2, 3, 4});
+    fs->putFile(Path("0:FILE2"), Bytes{5, 6, 7, 8});
+    fs->deleteFile(Path("0:FILE1"));
+
+    auto directory = getBlock(sectors, 0, 256).slice(0, 64);
+    AssertThat(directory,
+        Equals((Bytes{0xe5} * 32) + createDirent("FILE2", 0, 1, {2})));
+}
+
 int main(void)
 {
     try
@@ -124,7 +234,7 @@ int main(void)
 
 			layout {
 				format_type: FORMATTYPE_80TRACK
-				tracks: 10
+				tracks: 20
 				sides: 1
 				layoutdata {
 					sector_size: 256
@@ -148,6 +258,10 @@ int main(void)
 
         testPartialExtent();
         testLogicalExtents();
+        testBitmap();
+        testPutGet();
+        testPutBigFile();
+        testDelete();
     }
     catch (const ErrorException& e)
     {