dbffile - npm Package Compare versions

Comparing version 1.1.0 to 1.2.0

dist/dbf-file.js

@@ -13,2 +13,3 @@ "use strict";
 const iconv = require("iconv-lite");
+const path_1 = require("path");
 const field_descriptor_1 = require("./field-descriptor");
@@ -31,2 +32,3 @@ const options_1 = require("./options");
         this._recordLength = 0;
+        this._memoPath = '';
     }
@@ -65,8 +67,17 @@ /** Opens an existing DBF file. */
             yield utils_1.read(fd, buffer, 0, 32, 0);
-            let fileVersion = buffer.readInt8(0);
+            let fileVersion = buffer.readUInt8(0);
             let recordCount = buffer.readInt32LE(4);
             let headerLength = buffer.readInt16LE(8);
             let recordLength = buffer.readInt16LE(10);
-            // Ensure the file version is a supported one.
-            assert(fileVersion === 0x03, `File '${path}' has unknown/unsupported dBase version: ${fileVersion}.`);
+            let memoPath;
+            // Ensure the file version is a supported one. Also locate the memo file, if any.
+            switch (fileVersion) {
+                case 0x03:
+                    memoPath = undefined;
+                    break;
+                case 0x83:
+                    memoPath = path.slice(0, -path_1.extname(path).length) + '.dbt';
+                    break;
+                default: throw new Error(`File '${path}' has unknown/unsupported dBase version: ${fileVersion}.`);
+            }
             // Parse all field descriptors.
@@ -101,2 +112,3 @@ let fields = [];
             result._recordLength = recordLength;
+            result._memoPath = memoPath;
             return result;
@@ -117,3 +129,7 @@ }
             // Validate the field metadata.
-            validateFieldDescriptorss(fields);
+            validateFieldDescriptors(fields);
+            // Disallow creation of DBF files with memo fields.
+            // TODO: Lift this restriction when memo support is fully implemented.
+            if (fields.some(f => f.type === 'M'))
+                throw new Error(`Writing to files with memo fields is not supported.`);
             // Create the file and create a buffer to write through.
@@ -187,2 +203,3 @@ fd = yield utils_1.open(path, 'wx');
         let fd = 0;
+        let memoFd = 0;
         try {
@@ -194,2 +211,15 @@ // Open the file and prepare to create a buffer to read through.
             let buffer = Buffer.alloc(recordLength * recordCountPerBuffer);
+            // If there is a memo file, open it and get the block size.
+            // NB: The code below assumes the block size is at offset 4 in the .dbt, and defaults to 512 if all zeros.
+            //     Sources differ about whether the offset is 4 or 6, and no sources mention a default if all zeros.
+            //     However the assumptions here work with our one and only fixture memo file. The format likely differs
+            //     by version. Need more documentation and/or test data to validate or fix these assumptions.
+            let memoBlockSize = 0;
+            let memoBuf;
+            if (dbf._memoPath) {
+                memoFd = yield utils_1.open(dbf._memoPath, 'r');
+                yield utils_1.read(memoFd, buffer, 0, 2, 4);
+                memoBlockSize = buffer.readInt16BE(0) || 512;
+                memoBuf = Buffer.alloc(memoBlockSize);
+            }
             // Calculate the file position at which to start reading.
@@ -256,2 +286,25 @@ let currentPosition = dbf._headerLength + recordLength * dbf._recordsRead;
                                 break;
+                            case 'M': // Memo
+                                while (len > 0 && buffer[offset] === 0x20)
+                                    ++offset, --len;
+                                if (len === 0) {
+                                    value = null;
+                                    break;
+                                }
+                                let blockIndex = parseInt(substr(offset, len, encoding));
+                                offset += len;
+                                // Read the memo data from the memo file.
+                                // NB: Some sources indicate that each block has a block header that states the data length.
+                                // Our fixture data doesn't have that - rather, the data is terminated with 0x1A. The format
+                                // likely differs by version. Need more documentation and/or test data to figure this out.
+                                value = '';
+                                while (true) {
+                                    yield utils_1.read(memoFd, memoBuf, 0, memoBlockSize, blockIndex * memoBlockSize);
+                                    let eos = memoBuf.indexOf(0x1A);
+                                    value += iconv.decode(memoBuf.slice(0, eos === -1 ? memoBlockSize : eos), encoding);
+                                    if (eos !== -1)
+                                        break;
+                                    ++blockIndex;
+                                }
+                                break;
                             default:
@@ -265,4 +318,2 @@ throw new Error(`Type '${field.type}' is not supported`);
                 }
-                // Allocate a new buffer, so that all the raw buffer slices created above are not overwritten.
-                buffer = Buffer.alloc(recordLength * recordCountPerBuffer);
             }
@@ -273,5 +324,7 @@ // Return all the records that were read.
         finally {
-            // Close the file.
+            // Close the file(s).
             if (fd)
                 yield utils_1.close(fd);
+            if (memoFd)
+                yield utils_1.close(memoFd);
         }
@@ -337,2 +390,6 @@ });
                             break;
+                        case 'M': // Memo
+                            // Disallow writing to DBF files with memo fields.
+                            // TODO: Lift this restriction when memo support is fully implemented.
+                            throw new Error(`Writing to files with memo fields is not supported.`);
                         default:
@@ -364,3 +421,3 @@ throw new Error(`Type '${field.type}' is not supported`);
 // Private helper function
-function validateFieldDescriptorss(fields) {
+function validateFieldDescriptors(fields) {
     if (fields.length > 2046)
@@ -367,0 +424,0 @@ throw new Error('Too many fields (maximum is 2046)');

dist/field-descriptor.js

@@ -15,3 +15,3 @@ "use strict";
         throw new Error('Type must be a single character');
-    if (['C', 'N', 'F', 'L', 'D', 'I'].indexOf(type) === -1)
+    if (['C', 'N', 'F', 'L', 'D', 'I', 'M'].indexOf(type) === -1)
         throw new Error(`Type '${type}' is not supported`);
@@ -33,4 +33,4 @@ // size
         throw new Error('Invalid field size (must be 8)');
-    if (type === 'I' && size !== 4)
-        throw new Error('Invalid field size (must be 4)');
+    if (type === 'M' && size !== 10)
+        throw new Error('Invalid field size (must be 10)');
     // decimalPlaces
@@ -37,0 +37,0 @@ if (decs !== undefined && typeof decs !== 'number')

package.json

 {
   "name": "dbffile",
-  "version": "1.1.0",
+  "version": "1.2.0",
   "description": "Read and write .dbf (dBase III) files in Node.js",
@@ -5,0 +5,0 @@ "main": "dist/index.js",

README.md

@@ -7,3 +7,12 @@ # DBFFile
 
-- Supports `C` (string) , `N` (numeric), `F` (float), `I` (integer) , `L` (logical) and `D` (date) field types
+- Supported field types:
+  - `C` (string)
+  - `N` (numeric)
+  - `F` (float)
+  - `I` (integer)
+  - `L` (logical)
+  - `D` (date)
+  - `M` (memo) Note: memo support is experimental/partial, with the following limitations:
+    - read-only (can't create/write DBF files with memo fields)
+    - dBase III file version 0x83 only
 - Can open an existing .dbf file
@@ -10,0 +19,0 @@ - Can access all field descriptors

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Found 1 instance in 1 package

Fixed alerts

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Improved metrics

Total package byte prevSize

71484

increased by4.08%

Lines of code

547

increased by7.25%

Number of lines in readme file

109

increased by9%

Number of low supply chain risk alerts

1

decreased by-50%

Worsened metrics

Number of package files

9

decreased by-18.18%

No dependency changes