Fix: bypass 512MB postMessage limit for file transfer and add file integrity checksum by SukiSunYuhang · Pull Request #310 · Snapmaker/OrcaSlicer

SukiSunYuhang · 2026-05-11T07:52:54Z

Add download URL for file transfer, bypassing 512MB postMessage limit
Add checksum field for file integrity verification
Add origin_size field
Use URL-safe base64 for path encoding in /wcp_download/ route

Description

This PR addresses the file transfer failure for files larger than ~512MB. Previously,
both sw_GetFileStream and sw_GetActiveFile read entire file content into memory and
passed it through the WebView postMessage bridge, which has a hard limit around 512MB.
Files exceeding this size get silently truncated.

Changes

sw_GetFileStream

Replace in-memory file content transfer with a local HTTP download URL
Files are now served via HttpServer at /wcp_download/
The Flutter client downloads files via HTTP GET, avoiding the postMessage size limit

sw_GetActiveFile

Add origin_size (file size in bytes) and checksum fields to the response
Client can display file size and verify download integrity without extra requests

HttpServer

Add /wcp_download/ route that decodes URL-safe base64 back to the native file path
Add m_native_path flag to ResponseFile to skip UTF-8 encoding conversion for decoded paths
Add fallback path opening when native path fails

Checksum Algorithm

SHA-256 digest → standard Base64 (matching Flutter's base64Encode(sha256.convert(bytes).bytes))
Computed via streaming (64KB chunks) to handle large files without memory pressure

Tests

Verified sw_GetActiveFile returns correct file_name, file_path, origin_size, and checksum
Verified sw_GetFileStream returns a downloadable file_url
Downloaded a 16.7MB gcode file via the returned URL and verified SHA-256 checksum matches
Tested with is_zip=false on Windows 11

1. Add download URL for file transfer, bypassing 512MB postMessage limit 2. Add checksum field for file integrity verification 3. Add origin_size field 4. Use URL-safe base64 for path encoding in /wcp_download/ route @

Fix: remove in-memory fallback and magic number - Replace duplicated in-memory response logic with a simple retry using utf8_to_filesystem_encoding, then fall through to existing streaming path - Replace char buf[64*1024] with static constexpr + std::string @

LiuLikeQian · 2026-05-11T10:55:54Z

+    auto& server = wxGetApp().m_page_http_server;
+    std::string b64 = base64_encode(file_path.data(), file_path.size());
+    for (auto& c : b64) {
+        if (c == '+') c = '-';


line break;

LiuLikeQian · 2026-05-11T10:56:05Z

+    std::string b64 = base64_encode(file_path.data(), file_path.size());
+    for (auto& c : b64) {
+        if (c == '+') c = '-';
+        else if (c == '/') c = '_';


line break；

LiuLikeQian · 2026-05-11T10:56:17Z

+            else if (c == '_') c = '/';
+        }
+        // Pad to multiple of 4 for base64 decode
+        while (b64.size() % 4 != 0) b64 += '=';


line break；

LiuLikeQian · 2026-05-11T10:56:25Z

+        // Decode URL-safe base64-encoded path: revert '-'→'+', '_'→'/', then pad
+        auto b64 = std::string(trimmed_url.substr(strlen(WCP_DOWNLOAD_PREFIX)).ToStdString(wxConvUTF8));
+        for (auto& c : b64) {
+            if (c == '-') c = '+';


line break；

LiuLikeQian · 2026-05-11T10:56:32Z

+        auto b64 = std::string(trimmed_url.substr(strlen(WCP_DOWNLOAD_PREFIX)).ToStdString(wxConvUTF8));
+        for (auto& c : b64) {
+            if (c == '-') c = '+';
+            else if (c == '_') c = '/';


line break；

LiuLikeQian · 2026-05-11T11:00:06Z

-
+    // Convert UTF-8 path to filesystem encoding (auto-adapts for Windows UTF-8 mode).
+    // If m_native_path is true, the path is already in system encoding (e.g., from base64 decode).
+    std::string system_file_path = m_native_path ? file_path : utf8_to_filesystem_encoding(file_path);


on system langue setting to close utf8 support global language, and should pass for testing chinese path;

LiuLikeQian · 2026-05-11T11:00:42Z

    std::ifstream file(system_file_path, std::ios::binary);
+    if (!file && m_native_path) {
+        // Native path failed; retry with UTF-8 → filesystem encoding conversion
+        system_file_path = utf8_to_filesystem_encoding(file_path);


the same as above;

LiuLikeQian · 2026-05-11T11:01:04Z

+static std::string calc_sha256_base64(const std::string& file_path)
+{
+    std::ifstream ifs(file_path, std::ios::binary);
+    if (!ifs.is_open()) return "";


line break;

LiuLikeQian · 2026-05-11T11:02:17Z

-                    std::string zipname = generate_zip_path(oriname, targetname);
-                    json        res     = get_or_create_zip_json(oriname, targetname, zipname);
-                    wxGetApp().CallAfter([weak_self, res]() {
+                if (!self) return;


line break;

LiuLikeQian · 2026-05-11T11:02:54Z

+                    if (name_index == std::string::npos || path_index == std::string::npos) {
+                        wxGetApp().CallAfter([weak_self]() {
+                            auto self = weak_self.lock();
+                            if (self) self->handle_general_fail();


line break;

LiuLikeQian · 2026-05-11T11:03:06Z

-                        if (self) {
-                            self->m_res_data["name"]    = res["zip_name"];
-                            self->m_res_data["content"] = res["zip_data"];
+                        if (!self) return;


line break;

LiuLikeQian · 2026-05-11T11:03:16Z

+                } catch (std::exception&) {
+                    wxGetApp().CallAfter([weak_self]() {
+                        auto self = weak_self.lock();
+                        if (self) self->handle_general_fail();


line break;

LiuLikeQian · 2026-05-11T11:03:27Z

-                        self->handle_general_fail();
-                        return;
-                    }
+                if (!self) return;


line break;

Fix: add missing line breaks for all if/else statements Ensure consistent code style by adding proper braces and line breaks to single-line if/else-if/else blocks across HttpServer.cpp and SSWCP.cpp. @

Fix: add braces to single-line while statement @

Fix: remove try-catch blocks in sw_GetFileStream and refactor file path encoding in ResponseFile - SSWCP: Remove try-catch blocks added by PR Snapmaker#310 inside m_work_thread lambdas in sw_GetFileStream(), letting exceptions propagate naturally - HttpServer: Refactor ResponseFile::write_response to use m_native_path flag for encoding decision, with fallback to raw path when conversion fails @

…display (#360) * fix: downloadFileFromOrca fails when HTTP server port changes When the default port 13619 is occupied, the HTTP server switches to an alternative port. The C++ side correctly uses the dynamic port for loading the Flutter UI page, but sw_GetActiveFile() did not include the "url" field in its JSON response. The Flutter JS downloadFileFromOrca function falls back to a hardcoded http://127.0.0.1:13619/localfile/... when the url field is null, causing requests to time out. Fix: - Populate the "url" field with the actual port via get_page_http_port() in both the zip and non-zip branches of sw_GetActiveFile() - Normalize Windows backslash path separators to forward slashes - URL-encode the file path to handle spaces and non-ASCII characters consistently across all platforms * @ 1. Add download URL for file transfer, bypassing 512MB postMessage limit 2. Add checksum field for file integrity verification 3. Add origin_size field 4. Use URL-safe base64 for path encoding in /wcp_download/ route @ * @ Fix: remove in-memory fallback and magic number - Replace duplicated in-memory response logic with a simple retry using utf8_to_filesystem_encoding, then fall through to existing streaming path - Replace char buf[64*1024] with static constexpr + std::string @ * @ Fix: add missing line breaks for all if/else statements Ensure consistent code style by adding proper braces and line breaks to single-line if/else-if/else blocks across HttpServer.cpp and SSWCP.cpp. @ * @ Fix: add braces to single-line while statement @ * @ Fix: remove try-catch blocks in sw_GetFileStream and refactor file path encoding in ResponseFile - SSWCP: Remove try-catch blocks added by PR #310 inside m_work_thread lambdas in sw_GetFileStream(), letting exceptions propagate naturally - HttpServer: Refactor ResponseFile::write_response to use m_native_path flag for encoding decision, with fallback to raw path when conversion fails @ * Fix: bypass 512MB postMessage limit for file transfer and add file integrity checksum (#310) * @ 1. Add download URL for file transfer, bypassing 512MB postMessage limit 2. Add checksum field for file integrity verification 3. Add origin_size field 4. Use URL-safe base64 for path encoding in /wcp_download/ route @ * @ Fix: remove in-memory fallback and magic number - Replace duplicated in-memory response logic with a simple retry using utf8_to_filesystem_encoding, then fall through to existing streaming path - Replace char buf[64*1024] with static constexpr + std::string @ * @ Fix: add missing line breaks for all if/else statements Ensure consistent code style by adding proper braces and line breaks to single-line if/else-if/else blocks across HttpServer.cpp and SSWCP.cpp. @ * @ Fix: add braces to single-line while statement @ * @ Fix: remove try-catch blocks in sw_GetFileStream and refactor file path encoding in ResponseFile - SSWCP: Remove try-catch blocks added by PR #310 inside m_work_thread lambdas in sw_GetFileStream(), letting exceptions propagate naturally - HttpServer: Refactor ResponseFile::write_response to use m_native_path flag for encoding decision, with fallback to raw path when conversion fails @ * @ @ Add: cross-platform test scripts for port 13619 fallback verification @ * Fix: update Flutter web resources and SSWCP.cpp refinement - Replace Flutter web package with latest version from Flutter team - Update SSWCP.cpp with related adjustments * delete test case --------- Co-authored-by: YukiMacMini <yukimacmini@YukiMacMinideMac-mini.local>

SukiSunYuhang added 3 commits May 11, 2026 14:58

@

bdcbae9

1. Add download URL for file transfer, bypassing 512MB postMessage limit 2. Add checksum field for file integrity verification 3. Add origin_size field 4. Use URL-safe base64 for path encoding in /wcp_download/ route @

@

3dabfcc

Fix: remove in-memory fallback and magic number - Replace duplicated in-memory response logic with a simple retry using utf8_to_filesystem_encoding, then fall through to existing streaming path - Replace char buf[64*1024] with static constexpr + std::string @

Merge branch 'bugfix_syh' into bugfix_wcp

23ec3c4

LiuLikeQian reviewed May 11, 2026

View reviewed changes

SukiSunYuhang added 3 commits May 12, 2026 16:45

@

a31cecf

Fix: add missing line breaks for all if/else statements Ensure consistent code style by adding proper braces and line breaks to single-line if/else-if/else blocks across HttpServer.cpp and SSWCP.cpp. @

@

7ded2bd

Fix: add braces to single-line while statement @

LiuLikeQian merged commit c5b2393 into Snapmaker:bugfix_syh May 13, 2026

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Fix: bypass 512MB postMessage limit for file transfer and add file integrity checksum - #310

Fix: bypass 512MB postMessage limit for file transfer and add file integrity checksum#310
LiuLikeQian merged 6 commits into
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SukiSunYuhang:bugfix_wcp

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SukiSunYuhang commented May 11, 2026

Description

Changes

sw_GetFileStream

sw_GetActiveFile

HttpServer

Checksum Algorithm

Tests

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